UNIVERSITY OF ILLINOIS 
Agricultural Experiment Station. 


URBANA, JULY, 1899. 





BULLETIN No. 56. 





RECENT WORK ON THE SAN JOSE SCALE IN ILLINOIS. 


The work of this office on the San Jose scale for the years 1897 and 
1898 has been in part purely practical and in part scientific. It has 
included a continuation of the search for infested Illinois localities and 
a thoroughgoing examination of those detected, as begun in 1896; the 
inspection of Illinois nurseries and nursery stock as a basis for official 
certificates issued to nurserymen; the insecticide treatment of infested 
premises in Illinois, undertaken to arrest the spread of the scale in this 
State; the collection, study, cultivation, and introduction, into orchards 
of two fungus parasites of this scale; field experimentation with special 
insecticides and insecticide apparatus; and a study of certain minor 
points in the life history and cecology of this insect. 

The search for infested Illinois localities has resulted in the dis- 
covery of six * points not on the list given in ‘my last biennial Report, 
thus making twenty-five} such localities now known in Illinois. <A con- 
siderable increase of the area known to be infested at four localities 
already reported has also been thus made out. The nursery inspections, 
forty-three in number, made by my Assistants have covered thirty-four 
Illinois nurseries, besides one in an adjacent state examined by special 
request and arrangement. The cost of these inspections, as paid by 
nurserymen, ranged from $1.50 to $31.73, and averaged $10.43 each, of 


* Now eleven. {| Now thirty. 
241 


242 BULLETIN NO. 56. [ July, 


which $5.55 was for traveling expenses and $4.88 for the pay of 
inspector. 

The insecticide measures undertaken have covered thoroughly and 
carefully all the known points infested with the exception of six, at two 
of which the distribution of the scale was so widespread that it was 
impossible with the funds at the service of the office to go over the 
entire ground. At one of these (Richview) the premises worst infested 
were carefully treated and all those less seriously involved were sprayed 
sufficiently to prevent the spread of the scale from them for the season. 
At a second (Sparta) numerous orchard experiments with insecticides 
were made and most of the premises seriously infested by the San Jose 
scale were thoroughly and successfully infected with two parasitic fungi 
causing contagious diseases of this insect. These fungi, both obtained 
from Florida on a personal visit of the writer, were distributed to Illinois 
orchards partly by direct transfer of twigs and branches bearing infected - 
scales and partly by means of extensive artificial cultures of the fungi 
made for this purpose at my office. Both methods of infection were 
entirely successful, and one of these fungous diseases of the San Jose - 
scale is now well established at both Sparta and Richview. 

At Mt. Carmel, the third of these localities, all trees found infested ~ 
on our earlier inspections were thoroughly treated except those on one 
town lot to which the owner persistently refused us access. Later 
examinations have shown, however, that the scale was more widely 
distributed at this point, both within and without the town, than was 
known to us when this work was done, and much additional spraying is 
needed at and near that place. 

The occurrence of the scale at Browns, in Edwards county, and 
also on a farm near Worden, in Madison county, was not ascertained 
until my field parties had been called in, owing to an exhaustion of 
appropriations available; and at Villa Ridge, in Pulaski county, reliance 
on the efforts of the owner of an infested orchard to clear it of the 
scale by cutting out infested trees, proved to be ill founded. His work 
was not thoroughly enough done, and the scale still continues on his 
premises. * 

Our experimental insecticide work was done mainly with kerosene, 
either pure or in mechanical mixture with water. We have failed, so far, to 
find conditions under which this insecticide may be safely and success- 
fully used by orchardists generally for the destruction of scale insects. 

The points in the habits and cecology of the scale to which especial 
attention was paid were the length of life of the young scale and its 

* These premises have since been cleared of the scale by a destruction of every- 
thing on the place which could have become infested. 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. wate ee 


power of locomotion if born where it could not readily attach itself toa 
suitable plant. 


DISCOVERY OF NEw ILLINOIS LOCALITIEs.* 


The new Illinois localities found infested by the San Jose scale 
since the publication of my last Report are Dundee, in Kane county, 
Manito, in Mason county, Assumption, in Christian county, a farm 
near Walnut Prairie, in Clark county, one near Worden and another 
near Alhambra, in Madison county, a farm near Mt. Carmel, in Wabash 
county, and town lots in Browns, Edwards county.+ More extensive 
occurrence of the scale than hitherto reported was also found at Tower 
Hill, in Shelby county, at Mt. Carmel, in Wabash county, at Richview, 
in Washington county, and especially in the Sparta neighborhood, in 
Randolph county. Near the place last mentioned it has now been found 
by my inspectors in more than sixty orchards, scattered over an area of 
approximately twenty-five square miles. 

At Dundee, in Kane county, the presence of this scale was first 
observed in the course of a general inspection of premises made at the 
request of the owner November 8, 1897, by Mr. R. W. Braucher, an 
Assistant of this office. In one corner of an eight-acre lot was a small 
block containing about two thousand trees and shrubs of various kinds, 
including apple, peach, plum, cherry, gooseberry, and currant, and a 
considerable variety of deciduous trees. This block was slightly infested 
with the San Jose scale, occurring mainly on the apple, although a few 
were detected on peach and mountain-ash. The infested apple-trees 
came originally from a nursery in Missouri some two or three years 
before. It was difficult to believe, however, that they were infested 
when received, because of the comparative scarcity of the scale upon 
_ them when discovered in the fall of 1897. None of them were badly 
attacked, although in some cases the scale was well distributed through 
the top of the tree. A row of apple-trees eight or ten years old 
adjoined this block at one end, and short rows of young cherry and 
pear were separated from it, at a considerable distance, by beds of 
young evergreens. Rose-bushes, syringas, spireas, grape-vines, goose- 
berries, currants, plums, apricots, hard maples, and ornamental shrubs, 
were growing on various parts of this eight-acre lot, but no trace of the 
San Jose scale was detected on any of them. { 

* See map, Plate I. 

+ To the above should be added the following localities, discovered since this 
manuscript was prepared: Monticello, in Piatt county, a farm near Quincy, in 
Adams county, Summerfield, in St. Clair cour ‘y, and Albion, in Edwards county. 


+ These premises have since been completely cleared of the scale by a destruction 
of everything on the infested place which could harbor it. 


244 BULLETIN NO. 56. | [ July, 


At Manito, in Mason county, on the farm of Mr. P. B. Stem, about 
half of a twelve-acre peach and apple orchard, and twenty rods of osage- 
orange hedge adjoining were quite generally infested by the San Jose 
scale. Numerous other osage-orange hedges, extending in all directions 
in this infested tract and containing many nests of birds, were not 
visibly infested by the scale. The pest was evidently introduced to this 
place by means of six apple-trees obtained from the Pomona Nurseries, 
in New Jersey, ini891. These trees were first to die, but later the trees 
surrounding them gradually perished. 

At Assumption, in Christian county, in a small orchard on a city 
lot belonging to Mr. H. Tobias, a pear-tree was found badly incrusted 
with the San Jose scale, in the midst of a few other trees, apple, peach, 
and cherry, through which the insect was scattered less abundantly. 
The pear-tree on which it had apparently been introduced was obtained 
by mail from a Philadelphia nursery two years before. It had made but 
little growth, and was only about three feet high. Four other pear- 
trees received at the same time and from the same firm were not in- 
fested. 

At Walnut Prairie, in Clark county, two orchards infested by the 
San Jose scale were found as the result of a letter of inquiry addressed 
to me February 16th by Mr. E. H. Baird, of Marshall, Ill. One of these 
places, belonging to Mr. Kreager, had become infested from the other, 
belonging to Mr. J. Cline. On the latter, situated a mile and a half 
east of the station of Walnut Prairie, both apple- and pear-trees were 
infested, while on the former, plum- and apple-trees and currant bushes 
were involved. The precise origin of the scale at this place could not 
be clearly ascertained. It was, however, probably brought by means of 
pear-trees bought from a tree peddler at Marshall. 

Knowledge of the occurrence of the scale near Alhambra, in Mad- 
ison county, came to me as a result of a personal inquiry from Mr. L. A. 
Pearce, a farmer of that neighborhood. The infested apple orchard, 
owned by Mr. C. S. Frame, is three and a half miles northwest of 
Alhambra. About thirty trees, all large, were very badly infested, 
together with several large elm-trees near the orchard. The former 
owner of this place, from whom Mr. Frame had bought it a few months 
before, had obtained his trees from a great variety of sources, and it 
was consequently impossible to trace this outbreak to its origin. 

The occurrence of the scale in an orchard near Mt. Carmel was 
reported by Dr. J. Schneck of that place and verified by a visit of 
inspection made by my Assistant, Mr. Braucher, in October, 1898. It 
is there well distributed among about four hundred trees belonging to 
Mr. C. C. Lingenfelter, on a farm about two and a half miles from town. ~ 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 245 


These trees were bought in 1893 of a traveling agent for the nursery of 
John Siebenthaler, at Dayton, Ohio. 

At Browns, the scale occurs on peach, plum, and pear, a fact ascer- 
tained by Professor T. J. Burrill while attending a Farmers’ Institute at 
Albion, and verified by him and Dr. Schneck by the examination of 
several infested twigs. 

At Worden, the scale was found September 23, 1898, by Mr. Green 
in a farm orchard belonging to Mr. C. C. Hoxey, living in the outskirts 
of the town. It was evidently conveyed to this orchard by means of a 
plum-tree and several June-berry trees (Amelanchier) from the farm of 
Mr. C. S. Frame, near Alhambra, reported above. In Mr. Hoxey’s 
orchard the scale was very generally distributed through some two hun- 
dred fruit trees of various kinds, some but slightly infested and others 
badly incrusted. 


INCREASED AREA INFESTED IN OLD SITUATIONS. 


At Monroe Center, in Ogle county, where only a single infested 
tree had been found the year before, as stated on page eight of the 
Twentieth Entomological Report, Mr. Braucher found November 18, 
1897, a pear-tree, some scattered pear sprouts, and two Rocky Mountain 
cherry-trees slightly infested with the scale. 

On Mr. Jacob Winzeler’s place, near Tremont, in Tazewell county, 
where only half a dozen trees (Japanese pears) had been previously 
found infested, it appeared by an inspection made December 2, 1897, 
that the San Jose scale was obscurely present in different parts of the 
orchard on plum and peach, some of the latter from fifty to seventy-five 
feet distant from the pear-trees worst infested. 

At Tower Hill about eighteen infested cherry-trees were found on 
the premises of Mrs. J. Connor, living near the village. The origin of 
this colony could not be ascertained. The infested premises of Mr. 
Grisso, mentioned in my last Report, were at a distance of three miles 
from the town. Careful inspection of the latter place, made by both 
Mr. Green and Professor Summers, covering all trees in the vicinity of 
those originally infested, resulted in the detection of no dispersal of the 
scale except to one tree, at some distance, which had been grafted with 
a scion from one of the infested trees. This was said to be the only 
scion that had been cut from these trees originally infested by the San 
Jose scale. 

Conditions at Ernst, as reported by Mr. Braucher January 17, 1898, 
were particularly instructive. As stated in my article for 1896 (see 
Twentieth Report, page 9), only one infested tree had been originally 
reported from this place, and this had been at once thoroughly destroyed. 


246 BULLETIN NO. 56. [ July, 


A careful inspection made by an office Assistant some months later dis- 
covered no others in this entire neighborhood; nevertheless on the date 
of Mr. Braucher’s visit, several pear-trees and one peach-tree in the 
immediate vicinity of the tree originally attacked, and a plum-tree two 
or three hundred feet from it, were all found slightly infested, the plum- 
tree evidently by means of nesting birds. On this the scales were 
clearly most abundant on the forking branch of the tree supporting a 
last year’s nest. 

At Richview, where but three colonies had been previously reported, 
—one of which proved upon more critical examination to be an allied 
scale,—fourteen colonies of the San Jose scale on as many different 
premises were finally found. All these were in the vicinity of the town, 
and so far as known all had been derived from a common source. 

Careful study of this district suggested some interesting queries 
with respect to the mode of distribution of the scale and to variations 
in its attack. It was found, for example, to be very much more abund- 
ant in infested orchards upon young trees than upon old and large ones 
immediately adjacent. Indeed it was often impossible to find it upon 
any part of large trees standing beside small infested ones at so short a 
distance that the young must have been frequently conveyed to the 
larger trees. It seems possible that in such case the young scales per- 
ished because they were unable to reach a part of the tree from which 
they could draw sap. In several instances small numbers of the San 
Jose scale were found in the midst of orchards of considerable size at 
distances as great as half a mile from the nearest infested premises, and 
in others the scale was very sparsely distributed over a considerable part 
of an orchard not otherwise infested. Observations to this effect were 
made only in districts where the scale had become decidedly abundant 
and destructive at several points. It seems, in fact, to spread slowly 
and steadily from the points of first introduction until it reaches a certain 
abundance, when its distribution becomes so rapid and general that the 
attack may almost be said to become epidemic. Three methods of dis- 
tribution may be suggested in explanation of these facts: the well-known 
transfer by means of nesting birds; the probable transfer of the freshly 
hatched young by strong and long-continued winds; and the passage 
of human beings, particularly during the season of fruit harvest, from 
infested orchards to others in all directions and to considerable dis- 
tances. It will be seen at once that whenever this stage of general, 
sparse, and obscure dispersal has been reached, the complete extermina- 
tion of the scale in that locality is hardly to be expected without most 
thoroughgoing, oft-repeated, and long-continued insecticide measures. 

Serious as was the case at Richview, that in the Sparta neighbor- 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. amore 


hood was very much worse, for there a general survey of the region 
made by an experienced observer, Mr. R. W. Braucher, resulted in the 
discovery of the San Jose scale in larger or smaller numbers on no less 
than sixty-five farms distributed over an irregular area of about twenty- 
five square miles. Moreover, his inspection was incomplete, and the 
area infested is possibly still considerably larger. In one case the scale 
was even found abundant in a roadside hedge at a distance of a quarter 
of a mile from the nearest orchard; and as this whole region still 
retains a considerable amount of the forest which originally wholly 
covered it, there is undoubtedly in this district a general scattering of 
the scale which no inspection woulddetect. Its complete extermination 
here I judge to be impracticable without an expenditure of several 
thousand dollars and the adoption of drastic measures similar to those 
applied in the East for the destruction of the gypsy moth. 


INSPECTION OF NURSERIES. 


The widespread and active public discussion of the San Jose scale 
during recent years has had the effect to alarm many prospective pur- 
chasers and in many cases to prevent or postpone purchase, and to 
arrest the planting and extension of orchards. Several illustrations of 
this fact have come to my office in the form of inquiries concerning the 
damage to be anticipated in planting or developing orchards at speci- 
fied localities in this state and concerning the presence of the scale in 
specified nurseries, which inquiries were sometimes accompanied by a 
statement that contemplated purchases would be deferred until my 
reply was received. 

Further, several states to which our nurserymen are accustomed to 
ship stock, in some cases amounting to considerable annual sums, have 
passed laws prohibiting the importation into those states of any nursery 
stock not covered by an inspector’s certificate of freedom from injurious 
insects. In all such cases regular inspection of nursery stock grown 
within their own limits is of course provided for by law, but no such 
provision being made in Illinois, both local and outside trade was be- 
coming seriously embarrassed for lack of a system of inspection which 
would give assurance of protection to purchasers and enable nurserymen 
to meet the requirements of the export trade. Having at my call or 
already engaged under my direction trained, trustworthy, and experi- 
enced entomologists, capable of making expert inspections upon the 
results of which I felt entirely willing to base official certificates signed 
by myself as State Entomologist, it seemed possible to meet the some- 
what difficult situation, outside any requirement of law, by volunteering 
the services of the office to nurserymen on condition that the expenses 


248 BULLETIN NO. 56. 3 [ July, 


of inspection and travel were borne by those whose business was facili- 
tated and whose interests were served by the official certificates to be 
issued. Consequently, after advising with leading horticulturists and 
nurserymen and with the Governor of the State, I issued in July, 1897, 
a circular notice concerning the San Jose scale and other fruit insects, 
containing the following paragraph: 

‘‘As a guarantee of the freedom of Illinois nursery stock from this and other 
notably injurious insects likely to be conveyed in trade, the Entomologist offers to 
inspect the premises of nurserymen and other dealers at least once each year, and to 
give to the owner after such inspection a certificate setting forth the precise facts 
apparent with respect to the presence or absence of the San Jose scale and other 
insects dangerous to the property of customers. Such inspections will be made and 
such certificates issued only on application to this office, and on condition that the 
actual traveling expenses of the inspector and a fer diem of three dollars* are paid 
by the owner of the inspected property. ~ Special inspections of nursery stock 
imported for sale will also be made, so far as this may be practicable, on the same 
conditions and terms; but to insure such inspections requests should be made as long 
as possible in advance of the receipt of importations, with at least an approximate’ 
‘indication of the time when they are expected to arrive. Trips may thus be arranged 
which will provide for the largest possible number of inspections, and reduce the 
cost of each. Statements of receipts and expenditures under this head will be 
reported to the Governor and published in the regular reports of the State Entomolo- 
gist of Illinois.” 

Numerous applications were received in response to this proposi- 
tion, and twenty Illinois nurseries were inspected between August 10, 
1897, and April 25, 1898. The form of certificate issued to those whose 
premises were found free from dangerous insect pests was substantially 
as follows: 


‘This is to certify that on..3....0....: 2s. «+. All ASSistant One 
office, acting under my direction, examined the growing stock in the 
nursery Of. oe eee ee eae ee meee sleds ee +s yan SOUNG 1a 
of the San Jose scale or of any other dangerous insects likely to be 
transported to the injury of customers. 

‘This statement is invalid after July 1, 1898 [or 1899]. 

5S. A. FORBES, 
State Entomologist.” 


This form was slightly modified in individual cases to meet varia-_ 
tions in condition and requirement. In some cases, for example, the 
stock was inspected after removal from the ground, exposing the roots 
to examination, in which case the certificate was so framed as to show 
that fact. In other instances, the occurrence of some of the ordinary 








* Four dollars in 1898. 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 249 


injurious insects of the region capable of being conveyed on nursery 
stock to premises free from them necessitated a limitation of the terms 
of the circular to the insects or classes of insects absent from. these 
premises, or, if present, incapable of transportation in the nursery trade. 
No certificate was issued, however, which did not testify to the appar- 
ent absence of the San Jose scale. This insect was found, indeed, in 
only one Illinois nursery, and this was one which made a specialty of 
evergreens—not subject to attack by that scale. 

It was supposed that these inspections would commonly be made 
at or near the close of the growing season, when all important insect 
injuries of the year would be conspicuous and when, furthermore, the 
results of an inspection would remain good until the growing season of 
the following year was fairly well advanced. A certificate issued upon 
such inspection would apply to both the fall shipments of the current 
year and the spring shipments following, but would be valid no longer. 

The Illinois nurseries inspected during the period just mentioned 
were, as already said, thirty-four in number, ten in the northern, seven- 
teen in the central, and seven in the southern, part of the state. Eleven 
of these nurseries were inspected in 1897, and nine of these eleven with 
twenty-three others, or thirty-two in all, in 1898. The total number of 
nursery inspections for the two years was therefore forty-three. Four- 
teen of these inspections were made by Prof. H. E. Summers, fourteen 
by Mr. R. W. Braucher, eleven by Mr. E. B. Forbes, and four by Mr. 
E. C. Green. During 1897 Messrs. Braucher and Forbes were regular 
Assistants of the office and were detailed for service as inspectors as 
calls came in. They received personally the per diem earned, their 
regular monthly salaries being suspended for the time devoted to this 
inspection work. Professor Summers, on the other hand, was not at the 
time on continuous salary, and was engaged only as needed for this 
service. In 1898, Mr. Braucher was engaged as needed for necessary 
inspection, and paid only from the fees; Mr. Forbes was so engaged 
and paid for a part of his inspections, and for the remainder, while in 
service as a State Laboratory Assistant, he received the fee, the time so 
paid being deducted in computing his monthly salary. 

The total expenditures on account of inspections were $448.30, of 
which $209.45 were paid for services of inspectors, the remainder 
($238.85) being for expenses of travel. The average cost per inspection 
was thus $10.43. The receipts from nurserymen were $429.55, leaving 
a balance of $18.75 paid personally by the Entomologist to inspectors 
and not repaid by nurserymen. 























250 BULLETIN NO. 56. [ July, 
EXPENSES OF NURSERY INSPECTION, 1897 AND 1898. 

Nurserymen. Place. ee of Inspector. Receea é Paid 

inspection. nurserymen.|inspector. 
W. A. Watson & Son..|Normal..... Aug, -:10;0'97|-H.. E.'S, $ 9.03 $ 9.03 
Phoenix Nursery Co ..|Bloomington| ‘' 13,07) HS ES) 20.73 20.73 
Bryaniiceroon est eek Princeton. 5.4 )?40 20,8 O71 ni, be 15.95 15.95 
Jigen So wtelactebe eM weg agem Bloomington |Sept. 10, '97| H. E. S. 12.56 12.56 
W.H. & A. L. Tincher|Decatur..... 9425, 07) Rs WB 12.25 
Geo. Gould & Son..../Villa Ridge. .|Oct. 5 OF is ahs 4.00 4.00 
.431;5.Webster 3. ).s4.:. Centraliags<| 6,971 RoW B: 6373 6.13 
Augustine & Co....... Nonitialsaeras 3 OO 7t ra. eee: 15.61 15.61 
Theo. Bechtel........ Staunton....| ‘ 12,)’07|'H=E.S)} 13.84 13.84 
PePtusband 2545 asa Leanderville; ‘‘ 16, '97| R.W. B. 3.00 3.00 
Aaikss milan Kies nike Champaign |. ‘> 29,.°97) HESS: 1.50 1.50 
P.S. Peterson & Son. .|/Chicago ....|Mar. 7, 8, ’98| H. E.S. 8.75 8.75 
JW. Miller Cowss.c;. Freeportte ihe pee 8 Ob riaeo ae 6.50 6.50 
Piminewoettavocna be Freeportec co) ci") 10,5 O82 sss, 6.50 6.50 
Lebkicher'& Spitler,..|Freeport.42 0" 931,09] Eis eS. | ee ee 6.50 
Hoe Cotta. aes on see cnt Nursery.) 2 12, OSH Eos, 8.95 8.95 

ease Vaughan. ss Chica goy, U..)-e ee 14s Ooela tees. Fas 7.752 
I, DCUYOEd ert hanes Bloomington |April 4, ’98) H. E.S. 6.66 6.66 
R. Douglas’Sons...... Waukegan ..| ‘‘ 19,98] E. B. F. 18.76 18.76 
Rob't C. Uecke....... Harvard 723s} -# (225; 298i) Bale 21.07 21.07 
foGe Vaughan. sn 2 Chicago..... Aug. 25, '98| E. B. F. L1.03 11.93 
R. Douglas’ Sons..... Chicagov;+:. i> 27, “OS -E=Bar- 13.73 13593 
Spaulding Nurs. & Orch. Co..../Spaulding ../ ‘‘ 30, ’98) R.W.B. 10,92 10.92 
Phoenix Nursery Co../Bloomington |Sept. 1-4, '98; R W. B ater 30°94 
W.W. Thomas...... Makanda. i) 5,- 98] E. B..F: 3.04 3 04 
Ass ELGOTAGLY. mc sete et Makanda: «Sabb og ee ba 3.04 3.04 
Di We Leib & Son. < Makandas., ste" OGG) rs oe Ee 4.51 4.51 
W. A. Watson & Co.../Normal.... LO>6 27%.1 OO, avy. i, 8.54 8 54 
Kop ts. Uecke > ..0 = Harvard sci 7 ST both, Gas 2.00 2.00 
Galeener & Thacker ..|Vienna..... im Gr Bes LG 10.09 10,09 
Pon Gul Noenis 7 ge Bloomington; ‘' 8, Jos RIVY eB: 6.00 6.00 
Augustine & Co... ..3. Normal. nS 9g, '98| R.W. B. 6.10 6,10 
Arthur Bryant & Son..|Princeton...| ‘'15,16, ’98| R W. B. 16.50 16.50 
Alpha Nursery Co. ../Alpha.. ; 17, 98) R.W. B. 7.59 7.59 
L. 8. Frese (Forest Oak Nursery).|Coatsburg. . . | 19, 98; RW B. 12.69 12.69 

GustavKlarner(Quincy 

Star Nurseries)..... Oumcy>, 44 21, '98| R.W. B. 13.44 13.44 
PIOUATO. E iatas Gs ee Melville Sai 396-26; os. te Coats 3.29 3.29 
SUELO Ce ON ee aye Upper Alton| ‘ 26, ’98| E. C.G. 3.29 3.29 
Theo. Bechtel........ Staunton» jee SNe, PORT me Geta 2.00 2.00 
P. S. Peterson & Son..|Chicago.....j/Oct. 4, 5, °98| E B. F. 19.66 19.66 
Custer Brothers...... Normal..... RBS Ooh kee VV aks. Faere Goi 0 
Missing Link AppleCo.|Clayton..... We 522 OO 15 nr 19.25 19 25 
DiveeAI LS S015 oo hee Meee Dundee..... «8.20.0 QoL rosubee ks: 20.81 20.81 














In nearly all cases the nursery stock examined was still standing in 
the rows; a fact which made it usually impossible to ascertain anything 
directly with regard to the condition of the roots. 
cable inspection of large nurseries can give at best only a rather loose 
approximation to a knowledge of injurious insects infesting them—at 


least on a small scale and to an obscure extent. 


Indeed, any practi- 


Our inspectors could 


only walk through the nursery plats back and forth at intervals of 
several rows of trees, judging of the general condition of the planta- 


- 


1899. ] WORK ON THE SAN JOSE SCALE IN ILLINOIS. , 251 


tion, stopping now and then to examine an individual tree, and giving 
careful attention only to trees whose general appearance indicated the 
possibility of insect injury. Of course no premises were found entirely 
free from insects commonly classed.as injurious. In the great majority 
of cases, however, those present were kinds which would necessarily be 
left behind in the shipment of clean young nursery trees, and without 
exception all were common widespread insects of the region or of the 
state at large. 

It is clear, however, that no certificate, however carefully it may be 
drawn, or however thoroughgoing may be the inspection upon which it 
is based, should be taken as more than presumptive evidence of the 
entire absence of seriously injurious insect pests. Indeed, in the hands 
of any except a thoroughly reliable and honest nurseryman it is 
entitled to no credit whatever, but may be even worse than no certifi- 
cate at all, since it would be perfectly easy for an unscrupulous dealer 
to deceive first the inspector and then his customer, and this with little 
or no danger of detection. The inspector, of course, must take the 
word of the nurseryman as to the extent of his property, and can only 
presume that he has seen all the stock from which the owner is likely to 
draw for sale, for if deceived in this regard he has usually no means 
of detecting the deceit. On the other hand, there is no certain means 
of limiting the use of the certificate to stock actually grown by the nur- 
seryman or on the grounds where the inspection was made. Duplicates 
of it may be used, with perfect security from detection, upon any stock 
from any source, received perhaps long after the last inspection was 
made. So far as the official certificate tends to give a sense of security 
to the customer in dealing with a nurseryman he does not know or in 
whom, if known, he does not have full confidence, it is undoubtedly an 
evilinstead of a benefit; but notwithstanding these drawbacks to its use, 
it will be difficult, I think, to devise any satisfactory substitute for it, 
as it is now commonly worded and as it should be generally understood. 


INSECTICIDE TREATMENT. 


Heretofore and in other states under circumstances such as existed 
in Illinois in 1897, either nothing has been done in the general behalf, 
the San Jose scale being left to the care of individuals acting in their 
own interest, or laws have been passed establishing some state authority 
competent to deal with the economic situation. In Illinois an attempt 
was made to secure such thoroughgoing legislation at the biennial ses- 
sion of the state legislature for 1897. A bill establishing a state board 
of horticulture with ample powers of inspection and police was intro- 
duced in both houses and passed the senate by a unanimous vote, 


252 BULLETIN NO. 56. [ July, 


but was vigorously opposed while in the house and finally failed in 
committee, the only immediate result of the effort being an item in the 
general appropriation for the expenses of the state government appro- 
priating $3,000 to the State Entomologist ‘‘ for experiment, publication, 
and instruction concerning the San Jose scale, and for the inspection 
and disinfection of orchards and nurseries.” 

It thus became a part of the duty of the Entomologist to do every- 
thing possible to exterminate the San Jose scale in Illinois wherever it 
had been or might be detected or, if destruction should prove impracti- 
cable, at least to check its multiplication and spread as vigorously as 
possible, and to give to owners of infested premises full instruction with 
respect to precautionary and remedial measures. It was also clearly 
intended that the office should act to protect the state as far as practi- 
cable against the dispersal of the scale through the nursery trade. 
With a view to the discharge of these duties the following circular was 
issued in July, 1897: : 


An appropriation of $3,000 was made to the State Entomologist of Illinois by the 
General Assembly at its last session, ‘‘ for experiment, publication, and instruction 
concerning the San José scale, and for the inspection and disinfection of orchards 
and nurseries.” It is the earnest desire of the Entomologist that this sum may be 
used to the best advantage to disclose the present condition of the fruit interest of the 
state with reference to this pernicious insect; .to exterminate the scale promptly 
wherever in Illinois it has been or may be found; to protect the nurseryman and 
fruit grower as far as practicable against the chance of future invasion; and to assure 
the customers of Illinois nurserymen and of other dealers in fruit plants that Illinois 
stock offered for sale is free from this pest. 

It was the evident intention of the legislature to trust the control of this important 
matter to the public spirit and enlightened business enterprise of the private citizen, 
aided in every practicable way by the official Entomologist. It is the purpose of this 
circular to make to allinterested a cordial offer of information, advice, aid, and super- 
vision of insecticide operations, as far as the resources at our disposal will permit; and 
also to ask early and full information from all concerned with reference to the occur- 
rence or introduction, known or suspected, of the San José scale in Illinois. 


LOCATION OF COLONIES. 


It must be our first endeavor to discover promptly and to locate exactly all the 
colonies of this insect now established in the state. Eighteen such colonies have 
already been found, nearly all by an inspection of premises to which we have had 
reason to believe that nursery stock was imported at a time when the nurseries from 
which it came were infested by this scale. It is of great importance that we have at 
once full information concerning all importations into the state from places and at 
times such as to make it possible that the San José scale was conveyed by their means. 
I consequently earnestly request all to whom this notice may come that they will send 
to this office prompt and precise information with regard to the importation into 
Illinois of nursery stock or other trees or plants subject to its attack, which were 
grown in any of the following localities within the time mentioned after each: Cali- 
fornia, since 1873; eastern New Jersey, between 1886 and 1894; Maryland since 1887; 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 253 


Florida, since 1889; Washington State and Ohio, since 1890; Georgia and Louisiana, 
since 1891; Long Island, N. Y., since 1892; Delaware and eastern Massachusetts, 
since 1893. 

The plants thus far found subject to injury by the San José scale are the apple, 
pear, peach, apricot, plum, cherry, quince, grape, raspberry, blackberry, gooseberry, 
currant, and persimmon, among our fruits; the chestnut, hickory, pecan, English 
walnut, black walnut and almond among the nut-bearing trees; the oak, basswood, 
elm, catalpa, birch, poplar, and willow among our shade and forest trees; and a large 
miscellaneous list of trees and shrubs, including the rose, thorn-apple or red haw, 
crab-apple, wahoo, spirza, loquat, cotoneaster, flowering quince, flowering currant, 
acacia, alder, and sumach. This insect also seriously infests the osage orange, 
spreading with the greatest facility through the thick growth of the wayside hedge. 

It is very important that all supposed or possible cases of the appearance of the 
San José scale in Illinois be reported at once to this office, accompanied by twigs or 
pieces of bark illustrating the supposed attack. To all communications accompanied 
by such specimens prompt reply will be made, and energetic measures for its 
destruction will be taken wherever the scale is thus detected. 


EXTERMINATON OF THE SCALE. 


To owners of premises on which this scale is found the Entomologist will give all 
information and assistance necessary to the prompt extermination of the pest, sending 
an agent to inspect: the situation and surroundings, to give personal instruction as to 
methods of procedure, and to supervise and direct insecticide operations, An effi- 
cient spraying apparatus will also be furnished for use where this cannot otherwise 
be readily obtained. This proposition is made on the sole condition that the owner 
will destroy stock hopelessly diseased and will provide the necessary insecticide and 
the labor for its preparation and for its distribution to infested stock, and that the 
whole operation will be carried on and continued to the satisfaction of a representative 
of this office. Experience elsewhere has shown that expert assistance of this sort is, 
as a rule, necessary to insure success; and expenditure of public money in such an 
interest can be justified only on condition that everything is done needful to the 
accomplishment of the end desired. A 

The San José scale is commonly regarded by those best informed concerning it 
as the most dangerous and injurious insect enemy of American fruits. It now occurs 
in Illinois in comparatively small colonies, where in most cases it can probably be 
exterminated at small expense. Considering the enormous loss which is likely to fall 
upon the horticulture of the state if this highly destructive insect is allowed to spread 
generally throughout our orchards and to infest our nurseries, it is to be hoped that 
every person upon whose property it appears will regard the situation in the light of 
the public welfare as well asin that of his private interest, and that he will take 
without hesitation such measures as may be necessary to protect both. 

BULLETIN OF INFORMATION. 


An illustrated bulletin of information concerning the San José scale and its dis- 
tribution in Illinois has been published by the State Agricultural Experiment Station 
{Bulletin No. 48), and will be furnished on application to Prof. Eugene Davenport, 
Director of the Station. A later and more comprehensive article upon the subject 
will appear in the forthcoming biennial report of the State Entomologist, which will 
probably be ready for distribution this fall. * 


* For omitted section see page 248. 


254 BULLETIN NO. 56. [ July, 


In accordance with the propositions of this circular, preparations 
were made during the summer of 1897 for a thorough and general in- 
secticide treatment of all infested premises, to begin as soon as the 
leaves had fallen from the trees, this postponement being essential to 
any reasonable assurance that all the scales on an infested tree would 
actually be reached. 


DESCRIPTION OF APPARATUS. 


The principal apparatus used is a large and complicated machine 
sprayer consisting of a one-horse power gasoline engine, a three-cylinder 
force pump, and a large double galvanized-iron tank with a powerful 
gasoline heater beneath for making the solution of whale-oil soap. 
Besides this apparatus, intended for use in large orchards or in com- 
munities where a considerable number of infested places were separated 
by short distances, we had in use from one to three hand-sprayers of 
the kind ordinarily used in orchard work. 

The machine sprayer (Plate II.) is mounted on a two-horse baggage 
wagon, under the seat of which are placed the battery and the gasoline 
tank to supply the burners. Immediately back of these, on the first 
third of the floor space, is the engine. The large heating tank comes 
next. It is set close to the right side that there may be room on the 
left for the belt which connects the engine with the pump. The pump 
occupies the remaining room in the back. The wagon thus loaded 
weighs 2,400 lbs. 

The gasoline engine (Plate III., Fig. 1) which drives the pump was 
manufactured in the University Shops. It has a four-inch cylinder witha 
four-inch piston stroke. The gasoline vapor is made by the flow of air 
over a gasoline jet from a needle valve on the right side, this jet being 
caused by gravitation from a supply tank placed higher than the engine and 
above the wagon seat. Gas is drawn into the cylinder from the vapor 
chamber to fill the partial vacuum caused by the previous explosion, a 
valve to allow this being opened each time the piston passes the center. 
The vapor when under a back pressure of forty pounds is exploded by 
an electric spark caused by an inter-cylinder contrivance making and 
breaking the current from a sixteen-cell battery. The pulley wheel is 
nine inches in diameter and makes about four hundred revolutions per 
minute. The engine is rated at one-horse power. 

Just back of the engine is the tank, firmly attached to a three- 
eighths by one and a fourth-inch iron frame raised sixteen inches from 
the floor of the wagon. - There are six legs of the same material as the 
frame, each bolted to the floor. Beside these legs two braces extend 
forward from the upper part and are bolted to the flour, one on either 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. oD gies 


side of the base of the engine. The tank is of heavy galvanized iron, 
fifty-six inches long by twenty-six inches wide, and twenty-seven inches 
deep. Its capacity is one hundred and seventy gallons. A partition 
runs crosswise through the middle, and each section thus made has a 
twelve-inch opening in the top and a cap for the same. In the left-hand 
corner, toward the rear, each section empties through an inch pipe into 
the system leading to the pump. A valve on this pipe admits the shut- 
ting off of the section from the feeding system at will. Another valve 
allows the direct emptying of the section without passing its material 
through the pump. Each section of the tank is provided with like valve 
and arrangements, and contains a strainer so placed that all liquid pass- 
ing to the outlet must run through it. 

Beneath the tank are two sets of gasoline burners (Plate III., Fig. 2), 
each set having twelve burners, all constructed on the same principle as is 
the common plumber’s torch. Gasoline comes to them through a pipe 
on the right side of the wagon from a tank under the seat. To this tank is 
attached an air pump and a pressure gauge. While in use a ten-pound 
pressure is maintained. By means of valves, one or both sets of burners 
may be in use at one time, and the construction is such that each burner 
may be shut off or caused to burn low. The floor of the wagon under 
the tank is thickly covered with asbestos and cement, which protects the 
wood and forms a foundation for the pipes which support the sets of 
burners. Within the iron frame are two side- and two end-strips of gal- 
vanized iron which protect the burner flames from wind and help retain 
the heat beneath the tank. 

The pump is of the triplex type, having three one and three-quarter 
-inch-cylinders capable of a two and a half-inch-piston stroke. The 
pumping capacity is 0.07 gallon per revolution of crank shaft, or from 
2.8 gallons to 4.2 gallons per minute when run within recommended 
speeds, and the pump will operate against one hundred and fifty pounds 
per square inch. A one-inch feed-pipe enters from the tank, which is 
elevated, in the manner stated, above the body of the pump. The dis- 
charge may be through a one-inch pipe or through the series of four 
quarter-inch cocks arranged on a cross-pipe which is connected with 
the one-inch discharge. The belt runs on a twelve-inch pulley with a 
two and a half-inch face. There are two pulleys, one loose on the 
shaft. 

A three-eighths inch pipe is connected up with the discharge and 
the water jacket of the engine cylinder, and this cylinder again with the 
“feed-pipe, thus allowing a flow through the water jacket. ‘The rate of 
this flow is governed ‘by a shut-off valve on the jacket feed-pipe near 
the cylinder. When only two quarter-inch hose are in use this valve 


256 BULLETIN NO. 56. [ July, 


may be opened sufficiently to cause not only the circulation in the water 
jacket, but also to relieve the increased pressure on the two hose. 

Beside the main parts of the outfit, as above mentioned, there are 
two tool boxes, about one hundred and fifty feet of three-ply quarter- 
inch rubber hose, poles and extension rods for spraying higher parts of 
the trees, pails for carrying water, and gasoline cans. 

The larger tool box is 8.5 in. x 41 in. x 32 in. outside measure, 
and was made in this form that it might occupy the space between the 
tank and wagon box, on the left, when moving from place to place. In 
this box are the work clothes, a spade, hatchet, nozzles, reducers, 
wrenches, wire-cutters, packing, screw-driver, and other articles used 
in connection with the spraying operation. The smaller box is 12 in. 
xX Ig in. x 20 in., and was made to occupy the space between the engine 
and the tank. It contains the oils and smaller renewal parts for the 
engine. 

A large tarpaulin covers the whole apparatus, and by means of 
short ropes attached to its edges may be securely fastened to the wagon- 
box, so that in shipping, engine, tank, and machinery are all under 
shelter and protected from the weather. 


DETAILS OF TREATMENT, WITH RESULTs. 


At Dundee, Kane county, all the trees (apple, peach, and mountain- 
ash) upon which the San Jose scale could be discovered were dug out 
and destroyed in the presence of my Assistant, Mr. R. W. Braucher, 
November 20, 1897. Everything in the block of trees in which this in- 
fested stock was found was, in fact, so destroyed at this time except 
some shade trees—black walnut, horse chestnut, white elm, hard maple, 
birch, and basswood, and these were thoroughly sprayed with whale-oil 
soap. A few white-ash seedlings in this block were not sprayed. The 
apple-, cherry-, and pear-trees in the vicinity, and scattered soft maples, 
rose-bushes, and syringas next the infested block were sprayed, leaving 
without treatment only the ornamental shrubbery farthest from the trees 
infested. 

These premises were very carefully inspected again September 7, 
1898, by Mr. E. C. Green, of my office, and still more fully, October 
28 and 29, 1898, by Mr. E. B. Forbes, the first inspection to ascertain, 
for my own information, the effect of the insecticide procedure there, 
and the second, made at the request of the owner, to serve as a basis 
for a certificate of freedom from the San Jose scale and other injurious 
insects and fungous diseases. Both these skilled and careful observers 
reported after this interval of nearly a year from the time of treatment 
that there was no trace of the San Jose scale to be found on these 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. Log OST 


grounds; but to make assurance doubly sure I required the destruction 
of all stock on the infested premises which could possibly harbor and 
maintain the scale, designating the various lots and kinds of trees and 
shrubbery objected to. This requirement had been made good by January 
16th, and an unqualified certificate of apparent freedom from the San Jose 
scale and from all other dangerous insects and from fungous diseases 
capable of being transported with nursery stock to the injury of cus- 
tomers was issued under that date. 

At Monroe Center, in Ogle county, the single pear-tree originally 
first infested had been cut off close to the ground and burned by the 
owner, and the bark had been removed from the stump for some dis- 
tance below the surface. Two shoots three or four feet high which 
afterward grew up from this stump in the summer of 1897, showed no 
signs of the scale November 18th of that year. Traces of the scale were 
found, however,-on two eight-year old Rocky Mountain cherry-trees 
and on some sprouts of another pear-tree near by. All the infested 
bushes and trees on this lot and everything near by were thoroughly 
sprayed at this time with whale-oil soap—one hundred and fifty trees 
- and shrubs in all, including peach, pear, cherry, apple, and plum, grape, 
goosebery, currant, Rocky Mountain cherry, etc., and not a scale could 
be found on these or on any of the surrounding vegetation by Mr. Green, 
who visited this place September g, 1898, for the purpose of ascertain- 
ing the effect-of the treatment. 

On Mr. Jacob Winzeler’s place, two and a half miles south of Tre- 
mont, everything on the premises lable to attack by the scale was 
sprayed with whale-oil soap by Mr. Green March 28, 1898. Nine hun- 
dred and forty fruit-trees and shrubs were thus treated, and also fifteen 
large maple-trees about forty feet high. Ona visit of inspection made 
nearly six months later (September 14th) Mr. Braucher reported that he 
found a few living young San Jose scales, about half grown, on three 
large peach-trees, but that otherwise the premises seemed free from the 
- scale. The large maple-trees had been badly damaged by the spray, 
many of the lower branches having been-killed, evidently by the drip 
from the branches above. * 

On Mr. P. B. Stem’s place, three and a half miles north of Manito, 
two hundred peach-trees and twenty-five apple- and quince-trees were 
cut out, and also twenty rods of osage-orange hedge. Nine hundred 
trees were treated in this orchard, ranging in age from six to ten years. 
As none of these had ever been trimmed, about three days’ work of four 
men was required to prepare them for treatment. The spraying upon 
the 7th and 8th of April, 1898,. was followed by a heavy shower in the 


_ * All infested trees since destroyed. 


258 BULLETIN NO. 56. [ July, 


night, and the whole orchard was consequently sprayed again, the work 
being finished April 11th. Five months later, September 14~16, 1898, a 
critical inspection of this whole orchard was made by Mr. Green. On 
one peach-tree six living scales were found on new wood; on eight other 
peach-trees one or two scales each were found; and on each of six 
others from one to seventeen scales remained—mostly on new wood but 
some under bits of bark on the older growth. Ona single peach-tree a - 
colony of one or two hundred scales was found upon a branch, a part 
of which had evidently escaped the spray. Except for this single colony 
the total number of scales found on a very careful search of everything 
in and near this orchard which had been previously infested resulted in 
the discovery of about fifty living scales. 

According to the report of Mr. Braucher, as summarized in my 
last entomological Report (page 15), about ninety-nine per cent. of the 
San Jose scale in the orchard of Mr. Kiem, near Quincy, had been 
killed by two successive sprayings with whale-oil soap, made in the fall 
of 1896 and the spring of 1897. That this was not an overestimate of 
the efficiency of the treatment is shown by the report of Mr. Green, 
who visited this orchard April 13, 1898, and upon a rigid examination 
could find no living scales on the premises except on the trunk of one 
small apple-tree. He proceeded, according to his instructions, to treat 
thoroughly a third time all the trees (twenty in number) which had 
originally been badly infested, first scraping the trunks and removing 
the earth from about the bases. Hot soap solution was brushed on with 
stiff brooms up to the uppermost twigs, and these were sprayed except 
in a few cases where they were perfectly fresh and bright, evidently 
never having had any scale upon them. A very critical examination of 
this orchard made September 20, 1898, by the acute and careful in- 
spector, Mr. R. W. Braucher, showed that the San Jose scale in this 
orchard was, however, far from being exterminated, living scales being 
detected on several apple- and peach-trees which had been badly infested 
when the treatment of this orchard began. One apple-tree had been so 
badly incrusted with the scale that especial pains was taken to treat it 
thoroughly. The limbs were cut back to a few short stubs, the bark 
was scraped, and the tree was thoroughly coated with strong soap solu- 
tion by means of a brush. Pieces of bark clipped from this tree showed, 
nevertheless, that it was still slightly infested by the scale. 

At Paloma, visited April 17th, where one infested tree had been 
previously found, no scale could be detected. This tree had been taken 
out and burned, and others near it had been twice sprayed by the owner 
with whale-oil soap. 

Mr. Lowe’s orchard of five acres at Auburn, in Sangamon county, 


1899. |. WORK ON THE SAN JOSE SCALE IN ILLINOIS. 259 


was found by Professor Summers very generally infested, together with 
a hedge adjoining. This whole orchard and two rows of another 
orchard adjacent to it, not infested, were thoroughly sprayed by Pro- 
fessor Summers the first week in January, (898. The infested hedge 
was not treated, as the owner promised to destroy it. September 17, 
1898, it was found by Mr. Green that this orchard was by no means 
free from the scale, a considerable number of trees—apple, pear, peach, 
and plum—still showing from one to a dozen, twenty, or more, living 
scales. A few scales were also found upon apricot trees in an old 
orchard near by which was not: treated by Professor Summers. The 
situation at this place was on the whole quite unsatisfactory, and the 
premises will. doubtless become thoroughly infested again within the 
course of two or three years unless additional measures are taken for 
_ the destruction of the scale. The infested hedge mentioned above had 
been twice cut down, but had not been killed. : 

The infested trees on Mr. Henry Archer’s place, two miles from 
New City, in Sangamon county, were scattered through the western end 
of an orchard of about five acres. These were mostly young, but a few 
of them were large peach-trees, and others were of various sizes inter- 
mediate. All the very badly infested trees were, however, very small, 
and the scale had apparently spread but a short distance from them. 
About sixty trees were sprayed in this orchard in January, 1898, includ- 
ing, of course, all those visibly infested but going some distance beyond 
them. September 18, 1898, about seventy trees were found still infested 
with the scale, commonly not more than from ten to twenty specimens 
onatree. It was also found in an old orchard adjoining the one prin- 
cipally infested and which had not been sprayed by Professor Summers 
in January. 

At Assumption, in Christian county, the entire small orchard be- 
longing to Mr. Tobias on a city lot on which a single infested tree had 
been found, was sprayed February 12, 1898, by Mr. Green, and the 
pear-tree on which the scale had been brought to these premises was 
dug out and burned. This tree was one of six obtained by mail from 
a Philadelphia dealer. The remaining five were found in the hands of 
other citizens, all free from the scale except one belonging to Mr. Hiram 
Hooten,: which bore a few specimens sufficiently like the San Jose scale 
to give ground for suspicion. This tree was thoroughly sprayed by 
Mr. Green. September 20, 1898, on a single tree (a quince) Mr. Green 
found one San Jose scale; otherwise the trees on Mr. Tobias’s lot 
seemed free from the scale. | 

At Tower Hill early in February, 1898, two trees on Mr. Grisso’s 
place were cut out and burned, six were thoroughly sprayed with soap 


260 BULLETIN NO. 56. [ July, 


solution, and others adjacent were partly sprayed. On Mrs. Connor’s - 
place one tree was dug out and seventeen trees were sprayed. Septem- 
ber 21, 1898, Grisso’s place was found in rather bad condition. On 
three of the trees sprayed in February from three to eight living scales 
were detected by Mr. Green; on two adjacent trees not sprayed the 
San Jose scale was found, the trunk of one being covered and its upper 
branches infested; and on another part of the place, a hundred rods 
from the infested trees above mentioned, three trees were found badly 
incrusted with the scale, one an apple, one a plum, and one a flowering 
quince, <-1t3i8 probable that the scale-is generally distributed on Mr. 
Grisso’s place, and that only a thorough insecticide treatment of the 
whole of it can check its spread effectively. On the village lot of Mrs. 
Connor no scale was found at this time. 

At Herrick, in Shelby county, it.was found that the owner had 
removed the infested trees in August, 1898, and burned them up. A 
very careful examination of eight others, planted near them and sepa- 
rate from the main orchard of the owner, was made by Professor Sum- 
mers February 12, 1898, but no trace of San Jose scale could be found 
upon them. 

Spraying at Ernst, January 18 to 24, 1898, was attended by unusual 
difficulties and much delay owing to unfavorable weather, frequent rains 
probably washing off much of the soap. Work began January 18th and 
continued through the forenoon of the rgth, but was then interrupted by 
rain which lasted all the afternoon and into the night. The 2oth was too 
windy for orchard work, but spraying began again on the 21st and was 
followed by rain—in part violent showers—nearly all the 22d. On the 
afternoon of the 24th spraying began again, but was followed at night 
and in the morning by several hard showers. One hundred and sixty- 
four trees were sprayed in all, ranging from yearlings to trees fifteen 
feet high; and, besides these, rose-bushes, currants, gooseberries, honey- 
suckles, etc. ; 

Notwithstanding this unusual exposure to rains, Mr. Green could 
find March 24th only nine living scales on these premises, six under a 
bit of bark upon a pear-tree and three on a currant bush. A great 
part of the premises was, however, sprayed again, seventy-two bushes 
and trees being included inthe treatment. Only about four hours’ work 
was needed, but it took six days to do it on account of daily rains. 
October 12, 1898, Mr. R..W. Braucher carefully inspected everything 
on these premises and could not find living San Jose scale upon any 
shrub or tree. He also observed that the whale-oil soap had generally 
destroyed the Forbes scale (4Aspidiotus forbest), but that the scurfy scale 
(Chionaspis furfurus) was but little affected by the winter application of 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 261 


whale-oil soap. From seventy-five to ninety-five per cent. of the fruit 
buds on the peach-trees had been killed by the January treatment, but 
buds on the other trees were apparently uninjured. Spray applied dur- 
ing the latter part of March had, however, killed many buds on plum- 
and pear-trees. 

At the farm of Mr. E. L. Howard, in Edgar. county, a short dis- 
tance from Sandford, Ind., it was found in January, 1898, that all the 
infested currant bushes had been dug out and destroyed by the owner, 
and that the woodland brush next the infested field had been partly 
cleared off and burned. It was the owner’s intention, in fact, to com- 
plete this work the following spring as a safeguard against the possible 
perpetuation of the scale in this situation. A plat of quince bushes and 
some rows of apple-trees in the vicinity of the infested grounds were 
sprayed by Mr. Braucher at this time, although no San Jose scale was 
detected on any of these trees or shrubs. Another inspection made by 
- Mr. Braucher October 11, 1898, gave a similar negative result, and it 
seems likely that the San Jose scale has been exterminated at this point. 

At Mr. A. H. Evinger’s place near Vermilion, Edgar county, to 
which the scale had been transferred by purchase of currant bushes 
from the premises of Mr. Howard, just mentioned, the San Jose scale 
was found on only three currant bushes among some four hundred in 
the plantation, and on these it was so scarce as to make it little likely 
that it had spread to adjacent plants. All the currant bushes in this 
plantation, together with eighteen small plum-trees near by, were 
thoroughly sprayed January 4, 1898, and October 1ith no San Jose 
scale was to be found on this place. 

The colony on the place of Mr. Charles Eckert, three miles from 
Collinsville, was visited by Mr. Green February 18, 1898, with a view 
to its destruction. It had by this time made considerable progress, as 
is shown by a comparison of the observer’s notes with the statement 
published on page 1o of my last Report. Trees then slightly infested 
were found by Mr. Green in the last stages of disease from scale attack; 
and where one badly infested pear-tree was reported previously sixty pear- 
trees were now badly infested and some of them dead. Work here was 
retarded by rain and by the reluctance of the owner to allow his trees to 
be sprayed. Five trees were finally dug out and burned, however, and 
forty-eight sprayed. The spraying was, unfortunately, followed within 
twelve hours by about eight hours’ rain. Twenty-two trees were found 
still slightly infested on these premises September 27, 1898, when 
revisited by Mr. Green, the number of scales detected varying from one 
to twenty on each tree. 

At Mascoutah the infested premises described as_ belonging 


262 BULLETIN NO. 56. [ July, 


originally to John Baisch* were found in the possession of Charles 
Clements. The small orchard contained about one hundred trees of 
various sizes, and the place was in greatly neglected condition, black- 
berries, raspberries, and gooseberries having grown unchecked, to form 
a dense and almost impenetrable thicket under the orchard trees. . There 
were no fruit trees adjacent to this lot except in one direction, across the ~ 
street, and no scale could be found anywhere in the vicinity. It was 
abundant, however, on a row of peach-trees about the middle of the lot, 
and had spread from these to blackberries beneath. The owner declined 
to allow any trimming of trees or any removal of shrubbery, but Pro- 
fessor Summers made, December 8, 1897, a persistent effort to spray 
thoroughly everything on this lot, using nearly six hundred pounds of 
soap. The scale was nevertheless found by Mr. Green September 28, 
1898, on about thirty of these trees, the number detected ranging from ~ 
one to twelve per tree, except in a single instance, apparently over- 
looked earlier, of a peach-tree thickly infested throughout. _ 

At West Salem, visited by Mr. Braucher February 4, 1898, all the 
trees known to.be infested on Mr. Fishel’s premises were sprayed, to- 
gether with adjacent trees for six rows in one direction and four in 
another. Sixty-one trees were treated in-all, ranging from six to eigh- 
teen feet in height. From Mr. Braucher’s report of a visit made 
October 28, 1898, it appears, however, that this spraying was not carried 
far enough, as he found at the time a few infested trees outside the area 
sprayed, as well as eighteen within the area which still carried a very 
few living scales each. | 

The infested orchard on the farm of Mr. C. S. Frame, three and a 
half miles east of Alhambra, in Madison county, was treated February 
25, 1898, twenty-one trees being cut down and destroyed and thirteen 
others sprayed after heroic cutting back.. The weather continued steady 
for several weeks after spraying, and the soap could still be seen upon 
the trees a month after it was applied. Visited September 23d and 24th 
by Mr. Green, it was plain not only that the treatment was but partially 
effective but also that the scale attack had extended farther than was 
supposed at the time the spray was applied. From one to a dozen 
scales were found on each of twenty-five trees, apple, peach, pear, and 
plum, still standing in various parts of this orchard. The trees had 
-made an excellent growth, and the living scales remaining were usually - 
found on the trunk beneath a thick crust of the dead or in deep cracks 
where young shoots started out from the old wood. 

At Walnut Prairie both Mr. Cline’s and Mr. Kreager’s orchards 
were sprayed by Mr. Green March 15 to 18, 1898, fifty-six trees and 


* See Twentieth Rep. State Ent. Ill., p. to. 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. | 263 


fifty-five bushes on Mr. Cline’s place and sixteen large trees on Mr. 
Kreager’s. Operations here were much hindered by rains, and part of 
the spraying was repeated on this account. These premises were 
inspected by Mr. Braucher, October 13, 1898. Mr. Cline’s orchard 
still gave evidence of having been very badly attacked by the scale, and 
living scales were found upon it in sufficient number to reproduce the 
difficulty within two or three years. On Mr. Kreager’s place, originally 
infested from Mr. Cline’s, much the same condition of things was 
found. The transplanted plum-tree by which the scale was brought to 
these premises had been very severely cut back and very:thoroughly 
-treated with whale-oil soap, which was rubbed in by hand and applied 
so freely that it formed a pool around the base of the trunk. Neverthe- 
less, many living scales were found on this tree by Mr. Braucher in 
October, especially on the young growth of the year. Several other 
trees on these premises were likewise still infested with living scales, 
which were found also on two peach-trees not sprayed by Mr. Green. 
The imperfect result of the insecticide treatment of these orchards is 
doubtless to be attributed mainly to the accompanying rains. 

At Mt. Carmel, five trees were dug out and two hundred and sixty- 


~ two were sprayed, belonging to eleven different owners living on five 


adjacent blocks. About eighty feet of infested osage-orange hedge was 
also cut out and destroyed. Most of the trees were large and full of 
branches, necessitating much pruning as a preparation for the spray. 
One owner refused my agent admission to his premises, although an 
inspection on a previous visit had determined the presence of the scale 
on his trees. : 

Subsequent inspection showed that the scale was much more widely 
distributed at Mt. Carmel than was supposed at the time this spraying 
wasdone It was found, indeed, by Mr. Braucher, late in October, on no 
less than fifteen blocks, many of which had, of course, not been sprayed, 
and even on those which had been treated with the whale-oil soap it had 
not been completely eradicated from a single one. The failure of the 
insecticide to exterminate the scale is well illustrated by the fact that 
_ twenty-five trees and bushes were found infested in October upon a lot 
(Mrs. Deischer’s) where forty-eight had been sprayed the preceding 
March, and that twenty-three were still infested in an adjoining lot 
(belonging to Mr. R. K. Stees) where thirty-two had been sprayed by 
Mr. Green. : 

The situation at Richview proved on continued inspection to be 
much more serious than was at first anticipated, the scale being so wide- 
spread as to make it impracticable for us within the time remaining 
last spring and with the funds at my disposal, to complete the procedure 


264 BULLETIN NO. 56. [ July, 


for its extermination at this point. Instructions were consequently 
given to my field assistants, Mr. Braucher and Professor Summers, to 
spray thoroughly those orchards or parts of orchards in which it was 
present in destructive numbers, and to treat also all other infested 
vegetation whence it was likely to spread within a year to new territory, 
thus arresting the ravages of the insect where it was doing real injury, 
and preventing the extension of the area infested by it. These measures 
were taken with the expectation of returning to this locality after the - 
fall of the leaves in 1898 fora final treatment of these premises. All of 
the infested property on the ground of Mr. J. W. Stanton, where the scale 
was first discovered at Richview, was thoroughly sprayed with whale-oil 
soap in February, 1898,—some sixteen hundred trees in all,—except 
certain badly infested trees which were dug out and burned. In addi- 
tion to this the premises of Mr. Jasper Wilgus, separated from those of 
Mr. Stanton by a country road and a high hedge fence, were very gen- 
erally treated, several badly infested trees being destroyed and many © 
others sprayed. About an eighth of a mile of hedge was cut down and 
burned, and the stumps remaining were profusely sprayed with kero- 
sene. From the orchard of Mr. Chas. Cooper, all trees originally 
found infested had been cut out and destroyed, but a few remained 
infested February 14, 18908. 

One of the places worst infested, a mile south of Richview, on the 
estate of Mr. Newcome, contained about twenty-three hundred trees. 
The condition of the spring weather and the exhaustion of funds avail- 
able for the purpose prevented the thorough treatment of these premises, 
but the trees originally infested were all cut out and extensive spraying 
was done with the object of exterminating the scale from the orchard 
worst infested and of reducing its numbers in other parts of these 
grounds sufficiently to render its spread unlikely. Approximately five 
hundred trees were sprayed in all upon these premises, leaving only a 
few partially infested trees scattered here and there. Later all or nearly 
all of these were infected with a fungus parasite of the San Jose scale, 
as will be described in another section of this article. 

Half a mile north of the Newcome place a single apple-tree, in a 
garden belonging to Mr. B. F. Johnson, badly infested with the San 
Jose scale, was sprayed, together with two other trees adjacent to it. A 
single infested tree which had been detected in an orchard immediately 
west of Richview, rented by Mr. Hamilton, was dug out and destroyed 
by the owner. Although no scale could be found on any other orchard 
tree, eighteen or twenty trees immediately surrounding were thoroughly 
sprayed by Professor Summers, and a large osage-orange hedge beside 
this orchard was cut out. 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 265 


A prolonged inspection of one of Mr. Stanton’s orchards at this 
place, made by Mr. Braucher early in November, showed substantially 
the same results as in those previously described. The great mass of 
the scales had been killed, but everywhere enough remained to give 
origin to a new attack, which in a short period of years would equal in 
destructiveness the one suppressed by our insecticide operations. Fif- 
teen hundred and forty-four trees were sprayed in this orchard of dwarf 
pears, and of these, fourteen hundred and nine were examined by Mr. 
Braucher the first of November. Not less than one hundred and seven 
of these trees still showed the living San Jose scale—in a great majority 
of the cases in small numbers only, but quite numerous on here and 
there a tree. . ° 

As a general result of the operations above described it appears 
that the San Jose scale has been exterminated in seven™ out of twenty- 
one places treated, namely, at Dundee, Monroe Center, Sandford, Ver- 
milion, Ernst, Herrick, and Paloma, but that more or less conspicuous 
traces of its presence are to be found in all the fourteen others.+ On 
several of these fourteen premises it was wholly killed on many badly 
infested trees, but in none of them onall. Even at Quincy, where a 
single small orchard was sprayed, at intervals, three times in a very 
thoroughgoing manner, enough of the scales survived to reproduce the 
original condition in three or four years at most. The places where the 
scale was completely destroyed were those where it had made least 
headway and where everything seen to be infested was promptly cut up 
and burned, this destruction being reinforced in most of the cases by a 
general spraying of everything’in the immediate neighborhood on which 
the scale could live. There seems, on the whole, little likelihood that 
the spraying method can be depended on even where most thoroughly 
and persistently applied, to exterminate the scale on any place where it 
has had a few years to establish itself. On such a place the only sure 
remedy is the ax and the faggot, applied to every tree and shrub on 
which the scale is seen to have made a lodgment, supplemented by lib- 
eral spraying of all vegetation which may have become obscurely in- 
_fested. It is true that fumigation with hydrocyanic acid gas has occa- 
sionally been recommended as efficient for the extermination of the 
scale even where the trees are completely and heavily infested, and some 
experiments lately published, especially in a Report on the San Jose 


*Now nine. 

+Inspections made since the preparation of this manuscript show that the San 
Jose scale has apparently been exterminated at Villa Ridge alsoand on Mr. Winzeler’s 
place near Tremont. At both places, every tree upon which there was any definite 
reason to suppose that the scale was finally present, was cut out and destroyed. 


266 BULLETIN NO. 56. [ July, 


scale in Maryland,* seem to sustain this recommendation. The general 
judgment of economic entomologists will, however, doubtless support 
the following statement quoted from a letter by Dr. L. O. Howard, writ- _ 
ten December 14, 1808. 

‘‘ While hydrocyanic acid gas furnishes the most effective means 
of destroying the San Jose scale and many other scale insects, it is not, 
as some seem to suppose, an absolutely perfect remedy, and experience 
for many years has fully demonstrated, and also experience in the East, 
that here and there an occasional scale will escape this treatment, and, 
in the course of two or three years, it will be necessary to go over the 
plants again. In California, treatments are found to be necessary about 
every three years. Where the work is done with exceptional care, per- 
haps a longer period of immunity is sometimes gained.” 

In brief, the San Jose scale can clearly be kept in check by thor- 
ough spraying with whale-oil soap or by general fumigation with hydro- 
cyanic gas once in two to four years, according to the situation and the — 
rapidity of its multiplication; but it can be exterminated where it has 
once effected a lodgment only by drastic measures of destruction sup- 
plemented by careful spraying or fumigation, or by repeated treatment 
applied in every case just as soon and just as frequently as a watchful 
inspection gives any evidence of the presence of the scale. 


DIFFICULTIES OF COOPERATION. 


The state legislature, as has already been said, rejected in 1897 a plan 
of legal and authoritative control and substituted therefor a mere appro- 
priation to the State Entomologist, who ‘was thus provided with funds 
for an investigation and destruction of the San Jose scale, but was left 
without authority to compel action on the part of reluctant owners, or 
to proceed to act in opposition to their wishes. The success of the 
work of destruction was consequently dependent upon volunteer co- 
operation between the Entomologist’s office and the citizens most im- 
mediately concerned. There was commonly no difficulty in securing 
such. codperation, at least in the form of permission to enter upon 
premises and the contribution of a considerable amount of labor in the 
application of insecticides. It was much more difficult, however, to 
induce the responsible owner to share in any way the expense of opera- 
tion, some refusing absolutely, declining to acknowledge any responsi- 
bility to the community; others declining to bear any share of the 
expense until satisfied that the insecticide operation was fully successful; 
and still others agreeing, but neglecting, either to purchase the insecti- 
cides or to pay for them when furnished, as proposed in my office circu- 


*Bull. No. 57, Md. Agr. Exper. Station, Aug., 1898. 


1899.|.. . WORK ON THE SAN JOSE SCALE IN ILLINOIS. 267 


lar. Indeed, three owners out of the thirty or more concerned posi- 
tively objected to have their premises entered on. Two of these were 
finally prevailed upon by the use of tact and persistence, but the third 
successfully resisted the persuasions of the agent of my office, and his 
premises were necessarily left without treatment. As illustrations of 
the difficulties encountered, the following items from the reports of Pro- 
fessor Summers and Mr. Green will be of interest: 

‘« Stepping into the yard of Mr. ————_,” writes Mr. Green, ‘‘I met 
an angry old gentleman who vehemently ordered me to move on, saying 
that his trees did not need any inspection. I tried to tell him about the 
scale, and referred him to his neighbors who were having their trees 
examined, assuring him that there was no charge for the inspection or 
the work. He would listen to nothing, however, but said that he was 
old enough to care for his own trees and didn’t ask the state to look 
after him. The last legislature, he said, was a band of thieves and rob- 
bers, and had started a scale scare to furnish fat salaries for two of its 
favorites; then further remarked that a man-had been there some time 
before who had gone across his lot without permission, and that now he 
would be glad to see the last of me. I finally apologized for troubling 
him and left.” 

At walked out to the place of Mr. —, three miles 
from town. The oldest son, a man of about twenty-five, showed me the 
_ infested trees, the mother also coming along. Some Japanese plums in 
‘one corner of a large peach and apple orchard were in the last stages of 
disease, completely infested by the scale. In another lot were several 
pear-trees, all badly infested and some dead. Both mother and son 
tried to convince me that the trees did not need treatment, or at any 
rate that they could wash off the scales themselves with their own soft 
soap. I pointed out the trees which I was sure that it would be abso- 
lutely necessary for me to treat with whale-oil soap, but they said noth- 
ing. I asked if one of their sons could take me back to town that after- 
noon and bring cut the apparatus if it had come. They said the boys 
were busy and had no time to spare; but as a friend was to be taken to 
the train that afternoon, one of the girls hitched up a horse and I was 
allowed to ride with them. I found my spraying apparatus at the depot 
and sent back a note by the girl asking that the team be sent for it in the 
morning. Starting out to the place on foot, I met the team with a girl 
_ driving. She said she was going for a load of brick, and would not 
bring out my material without orders from home. I presently found a 
neighbor of the family who agreed to bring my apparatus out that day 
as he returned from hauling a load of wheat to town, and I sent word to 
Mr. — that I would be out to spray his trees, asking him to have 














268 BULLETIN NO. 56. [ July, 


water hot that we might go to work without delay on my return. He 
looked more surprised than pleased when I came back with the appa- 
ratus, and there was no hot water. It threatened rain, and was then too 
late to begin, so I contented myself with their promise to have hot 
water ready in the morning. ‘The next day, while the boys were heat- 
ing the water, I pruned the trees. The boys finally helped in spraying 
and took the machine back to town, but the owner flatly refused to pay 
for the soap. The elder son, who took the apparatus to the station, 
became quite friendly before we separated, and told me that when I 
came back the second time they talked of getting the shot-gun and 
driving me off the place.” 

At another town, where the trees and bushes on a village lot were 
thoroughly infested by the scale, Professor Summers was met at first by 
a refusal to give him admission to the grounds. He ignored the refusal, 
however, and continued his preparations, entering upon a good ‘natured 
conversation with the owner. Seeing a large soap kettle at hand, he 
asked the use of it for boiling up his whale-oil soap. This was refused 
on the ground that the kettle belonged to the owner’s father and that it 
‘‘might be called for any minute.” By inquiry in the neighborhood 
another kettle was found, and this was hired at fifty cents a day. The 
owner of the infested trees, on his way to town to consult a lawyer, met 
a neighbor who told him not to interfere with his unwelcome visitor who, 
if an agent of the state, was probably acting under authority of law. 
This very reasonable but mistaken supposition served our purpose, and 
no further objection was made, although all assistance was steadily 
refused. The work was thoroughly done by Professor Summers, and 
no charge was made by us for materials used. 

As an example of the cordial spirit in which our propositions were 
‘commonly received, Mr. Green’s account of his experience at Manito 
may suffice. 

‘‘Visited, according to instructions, the farm of P. B. Stem, three 
and a half miles north of Manito. Walked out in the morning and 
found the owner plowing, He at once put away his horse and showed 
me the worst infested section of his orchard, spending the rest of the 
day with me in examining trees and hedges. We found that the scale was 
scattered through something more than six acres and had also infested 
twenty rods of hedge. Learning that the soap necessary to thorough 
insecticide treatment would probably cost about $30, he asked me if I 
wished the money at once. The next day he hired an additional man 
for the work and gave also his own time and that of his son. We all 
worked two days in pruning trees to be sprayed, and afterwards one of 
us cared for the fire, another worked the pump, and the remaining two 


18990. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 269 


applied the spray. Everything I asked was cheerfully done. Trees too 
seriously damaged for treatment were cut down and burned over their 
stumps, and a row of osage-orange hedge especially valued by the owner 
because in a year or two it would yield valuable posts was also cut out 
by my advice and thoroughly destroyed. Mr. Stem made five trips to 
town On my account, gave five days’ work of three men, sacrificed about 
two hundred trees besides the hedge, and put himself to considerable 
inconvenience in his farming ‘operations, as his teams were left idle 
when his oats should have been planted.” 


GENERAL INSECTICIDE PROCEDURE. 


The field assistants responsible for the spraying of infested orchards 
were Professor H. E. Summers and Messrs. E. C. Green and R. W. 
Braucher. Their methods were, of course, substantially the same. 
When hand sprayers were used the soap solution (two pounds to the 
gallon of water ) was made in large soap kettles, which it was possible 
to find in every neighborhood. To diminish the labor and expense, 
and likewise to insure a more thorough application of the insecticide, 
trees to be sprayed were pruned and cut back as much as the owner 
would permit. If the trunks of the trees were rough they were scraped 
to remove loose bark, and if the scale was found upon the trunk the 
earth was scraped away to the surface of the upper roots. The assistant 
always directed the spray himself, depending on the aid of owners for 
the rest of the work. In distributing the insecticide, limbs and branches 
were followed out one by one with the nozzle in a way to make sure 
that the spray reached every portion of the surface. Trees were fre- 
quently sprayed from opposite directions, especially if the wind were 
blowing considerably. Trees so covered with the scale that the surface 
of the bark was generally concealed were commonly cut out and burned. 
When the machine sprayer was in use two men from my office traveled 
with it, and two lines of hose were commonly used at once, with two 
spray nozzles for each. The soap solution was in process of {prepara- 
tion in one of the tanks while the spraying was emptying the other, 
and the spraying machine was thus kept continuously at work. For this 
continuous operation of the apparatus, however, a third;man was re- 
quired to attend to the engine and make the soap solution. 

The progress of the work was very much delayed and continuously 
embarrassed by the unusually wet and open winter. Frequent rains and 
sleets hindered orchard work or made a repetition of it necessary, and 
the wretched condition of the roads blockaded the machine.sprayer for 
“weeks at atime. We also found this large and heavy apparatus incon- 
venient for our purpose owing to difficulties of railroad transportation. 


270 : BULLETIN NO. 56. [ July, 


It could only be moved on a flat car,—not always to be had at call,— 
and loading facilities at small stations were sometimes insufficient for 
the handling of it. These experiences, together with the partial failure 
of the engine, led towards the end of the season to a substitution of 
hand equipments entirely for the machine sprayer, three of these being 

in the field at once during the latter part of our operations. 


AN EFFICIENT FUNGOUS DISEASE.* 


Notwithstanding the quantity that has been done and written— 
much of it by myself—concerning the use of the bacterial and other 
fungus parasites as a means of spreading contagious disease among in- 
sects for their destruction, it can scarcely be said that this insecticide 
method has been reduced to practice with entire success for so much 
as a single insect species. In the nearest approximation to a practical 
method yet’ made, the use of Sforotrichum for the chinch-bug, the 
results have been from the beginning s9 equivocal and so variable that 
this method has never yet been recommended from this office as gener- 
ally available or in any way trustworthy. It is with especial satisfaction, 
consequently, that I now report a series of experiments with a fungus 
parasite of the San Jose scale, first successfully applied by Prof. P. H. 
Rolfs, of the Florida Agricultural Experiment Station, which gave in our 
hands during the summer of 1898 great promise of usefulness as a strong 
and steady check upon the increase of this orchard pest. 

The conditions of experimentation with this fungus are fortnieeele 
very favorable to tangible and precise results. The scale insects being 
motionless, we are able to keep the identical individuals treated under 
continuous observation without artificial management; and the fungus 
used being one not native to the San Jose scale, the results of experi- 
mentation are not liable to be clouded by its spontaneous occurrence 
either before or after the experiment is begun. It has been very easy, 
consequently, to demonstrate the success or failure in every case, and 
the results may be accepted as unequivocal. 

The existence of this parasite of the San Jose scale was first 
brought to my notice by a letter from Prof. John B. Smith, written 
January 5, 1897, informing me that Professor Rolfs, of Florida, seemed 
to have found a specific organism which ‘‘had cleaned out some infested 
orchards in Florida and promised to control the scale completely.” He 
further quoted Professor Rolfs to the effect that the fungus had with- 
stood quite a low temperature, and that it was a constant parasite of a 
scale on the oak. He was also kind enough to send me a small quantity 


* See Plate IV., Fig. 7, for an illustration of the characteristic growth of Sph@- : 
rosttlbe coccophila from the edges of a San Jose scale killed by this fungus. 


NS 


1899.]_ WORK ON THE SAN JOSE SCALE IN ILLINOIS. 271 


of a culture received from Professor Rolfs purporting to be that of the 
‘scale fungus mentioned. 

The condition of this material from Professor Smith was not such 
as to encourage attempts at cultivating it, and I obtained instead, direct 
from Professor Rolfs, early in February, 1898, some limbs of the water 
oak infested by the common scale of that species, Aspidiotus obscurus, 
many of which had been killed by the fungus parasite in question— 
Spherostilbe coccophila Tul. In the letter accompanying this material 
Professor Rolfs informed me that in order to introduce this fungus into 
orchards infested by the San Jose scale it was only necessary to tie a 
piece of a branch bearing the fungus to some portion of the infested 
tree. February 27th he also sent me a small amount of Spherostilbe 
on the San Jose scale itself, the product of an infection made by him 
the preceding year. 

From the dead oak scales (Asfpidiotus obscurus) received from 
Florida in February, 1898, cultures of the fungus were. begun March 
4th, by my assistant, Ernest B. Forbes, at first on gelatine, then on 
boiled potato, and finally on corn meal and milk, and corn meal and 
beef broth. Although the inoculations were all made from the insect 
itself, all the material proved to be much contaminated, containing 
especially Penzcelium, Pestalozzia, and a liquefying bacillus. Careful 
separation cultures were thus necessitated, and by transfer from these, 
perfectly pure cultures of the Spherostilbe were finally obtained. 

The arcuate conidial spores of this fungus may germinate within 
four or five hours, and the growing mycelium acquires a characteristic 
pinkish color usually within five days. Vigorous growths of the fungus 
developed identical arcuate spores within a week from the time of in- 
oculation, this fruiting stage being indicated to the naked eye by the 
appearance of patches of a deep red color in the lighter pink of the 
mature mycelium. In one case a culture begun May 17th on bread 
soaked with sweetened milk, developed spores profusely by May 2oth. 
It proved extremely difficult to obtain the conidial stage of the fungus, 
or fruiting bodies of any kind, on peptonized gelatine, and scarcely less 
-so on boiled potato, but cultures on corn-meal batter made up with beef 
broth, or on pieces of bread saturated with the same, yielded the spores 
very readily and in great abundance, the whole infected surface pres- 
ently becoming a bright scarlet color, and being covered with a thick 
dense layer of elongate, curved conidia. A considerable amount of 
moisture seemed necessary to a full development of the fungus, and 
several of our failures in the beginning were apparently due to the fact 
that the medium was kept too dry. 

By May 2tst we had grown a considerable quantity of this fungus 


\ 


292 BULLETIN NO. 56. . [ July, 


on corn meal and beef broth as a preparation for extensive inoculations. 
of the San Jose scale in the orchards of southern Illinois. In the 
meantime a personal visit to the peach and pear orchards of northern 
Florida gave me reason to expect a favorable result in Illinois, and it 
likewise put me in possession of a considerable amount of fresh mate- 
rial in the form of twigs of trees infested by the oak scale killed by the 
Spherostilbe spontaneous on that insect. 

My principal observations in Florida were made on the 2oth of 
March in the vicinity of De Funiak Springs, when, in company with 
Professor Rolfs, of the Florida Agricultural Experiment Station, 1 care- 
fully examined three peach orchards. In the first of these, the Rose 
Hill orchard, there were but very few of the San Jose scale to be found, 
the number having greatly decreased within the last four years. These 
trees had been sprayed with rosin, potash, and sulphur during the winter 
of 1893 and 1894, but had never been artificially infected with the - 
scale fungus. We found, nevertheless, on a single tree a very few speci- 
mens of the San Jose scale with a fungus parasite which seemed to be 
the Spherostilbe coccophila and was so taken by us at the time. Subse- 
quent study on my return showed, however, that the fungus in this 
orchard was of a form closely related to S. coccophila, but of a species 
apparently new. It is distinguished not only by the smaller and much 
more strongly arcuate conidia, but also by strongly marked culture 
characters. The color of a mature culture, for example, is not red but 
a dusky brown with a slightly reddish tinge, and identical culture pro- 
cesses and media with those which yield the arcuate conidia of Spheros- 
tilbe coccophila give with this only masses of minute oval spores.” 

A second orchard, belonging to Mr. Mellish, had originally been 
heavily infested with the San Jose scale, but this had now almost 
entirely disappeared. The scale in this orchard had been inoculated in 
August, 1897, by tying to branches of the infested trees pieces of twigs 
of the oak bearing the scale fungus. At the time of my visit only a very © 
few living scales could be found, and among the dead occasionally 
one still remained with an obvious growth of Sphe@rostzlbe projecting 
from beneath the edge. This scale fungus was found not only upon 
trees to which infested twigs had been tied, but upon others adjacent to 
them, indicating a spread from tree to tree. According to the owner’s 
statements the surface of many of these trees had been conspicuously 
reddened by an abundant development of the fungus on the scale, these 
growths having subsequently been removed, with the dead scales them- 


* Letters received from Professor Rolfs since my visit to Florida notify me of the 
frequent finding of this fungus there on the San Jose scale and other species. 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 27 


selves, by exposure to the weather. The trees in this orchard were in 
very good condition, showing but little effect of the scale attack. 

The third orchard visited, that of Mr. Thalimer, was in very much 
worse condition, the fungus having been introduced too late to save 
many of the trees. The plat contained two hundred and seventy-five 
peach-trees, three years old, which had become infested two years 
previously by extension of the scale from the premises of a neighbor. 
Nine-tenths of the trees in this orchard were dead, according to the 
owner's estimate, many of them those to which pieces of oak branches had 
been tied in July of the previous year. Where the trees and the scales 
upon them were still living, the scale fungus could yet be found 

_ From the history and condition of these orchards and from other 
observations made upon this visit it seemed clear that the Spherostilbe 
could be made useful, especially where for any reason immediate insec- 
ticide work could not be done, but that it would at best serve only as a 
strong check upon the multiplication of the scale and not as an efficient 
means of its complete extermination. I consequently decided to apply 
it in Illinois on those premises only which we could not reach with the 
insecticide spray owing to the exhaustion of funds available for this field 
work. The most important region remaining without insecticide treat- 
ment was that at Sparta. Some orchards at Richview likewise had been 
only imperfectly sprayed, and others remained heavily infested and in 
condition to afford a means of testing the efficiency of this fungus 
parasite. 

This scale fungus was distributed to orchards at Sparta and Rich- 
view by Mr. E. B. Forbes on three separate visits; one from April 30th 
to May 5th, the second from May 28th to June 7th, and the third on 
June 23d. Thirty trees belonging to Mr. James Newcome, were thus 
infected near Richview, and three hundred and fourteen trees, belonging 
to twenty owners, in the Sparta district, as follows: 


S. A. Blair, 6 trees. H: A, W. Otten;5 trees: 
Henry Bodiker, 18 trees. Jefferson Porch, 35 trees 
Robert Conch, 1 tree. Lowis«Pritz;\s tree: 

James Davison, 8 trees. J. W. Robinson, 85 trees. 
Henry Lout, 6 trees. fohne>teel> 7-trees. 
George Lyons, 4 trees. Jacob Stahlman, 4 trees. 
Fred Marshall, 1 tree. J M. Temple, 76 trees. 
John McHenry, 3 trees. Silvenus Wilson, 7 trees. 
Riley McKelvey, 11 trees. James Wood, Sr., 8 trees. 
Sidney McKelvey, 2 trees. James Wood, Jr., 26 trees. 


At the earliest visit only infected scales on pieces of bark or twigs 
of oak obtained from Florida were used. The twig or bark with the 
fungus on it was tied to the upper side of a limb, as high up on the 


274 BULLETIN NO. 56. [ July, 


branch as the infestation was severe and in such a position that the 
southwest rains would readily strike it. From one to a dozen pieces 
were placed on a single tree, according to the size of the tree and the 
abundance of the scale, three or four being the commoner number. 
On the second visit, beginning May 28th, only artificial cultures of 
Spherostilbe were used, mostly those grown on corn meal or on pieces 
of bread. About a half inch square of the culture material was softened 
for a short time with water, and mixed with fifty centicubes of water, 
and the liquid was spread with a sable brush on the spot selected. The 
infected spot was then covered by wrapping the branch with a strip of 
wet duck four inches wide and forty inches long, the wrapping being 
fastened with a string. These strips were wet a second time on the 
following morning and were removed in twenty-four hours after appli- 
cation, the object of this procedure being to keep the culture material 
continuously moist until the spores had time to germinate. That this 
was done was shown by the fact that particles of the fungus were 
generally whitened by a mycelial growth from the germinating spores by 
the time the cloth was removed. The infected spot was then marked by 
a white string for convenience in subsequent inspection. 

The first such visit of inspection was made at Sparta by Mr. Forbes 
May 27th, three weeks after the infected twigs were put in place. At 
this time a few dead scales were found in the vicinity of the twigs, but no 
certain evidence of the spread of the fungus was obtained. On the next 
inspection, June 21st, a scale dead with Spherostilbe, and showing the 
fungus in the form of a fruiting growth, was found on a tree to which a 
corn-meal culture had been applied May 28th. Thecloth wrapping had 
been accidentally left on this tree, and the fungus had grown under its 
protection. July 6th, about two months after the first infection of these 
trees, the fungus had taken effect upon adjacent scales in practically 
every case where they had been originally abundant and the infection 
material had been liberally applied, but in no case was the growth on 
the tree profuse nor even generally visible even on the scales immediately 
adjacent to the infection material. When only a few scattered scales 
were present no start had been made. Returning to the same trees 
September 1st, we found the fungus was by this time growing vigorously 
everywhere, spreading downward in some cases as far as five or six feet 
and on lateral branches from the one to which the infection had been 
applied, as far as a foot beyond thefork. The upward spread, however, 
was not so great, the spores being evidently disseminated mainly by 
washing down; and there was nothing to indicate the spread of the fungus 
across an air space. On one tree six inches in diameter, for example, 
on Mr. Temple’s place, the fungus had spread downward about two feet, — 


1899.] . WORK ON THE SAN JOSE SCALE IN ILLINOIS. 275 


as far as the scales extended, and upward not at all. From another 
piece on the same tree the fungus had spread upward a foot and a half, 
downward two and a half feet, and thence an equal distance on a lateral 
branch. From still a third piece it had spread downward three and a 
half feet and out six inches ona branching twig. Another tree five 
inches in diameter, to which six pieces of bark had been tied, was so 
generally covered with the fungus infesting the scales that it was difficult 
to say whence and how far it had spread. Excepting the smaller and 
upper twigs and branches, the entire tree was infected. In some places 
on this tree the lateral spread must have been at least six feet. Another 
_ tree in this same orchard, to which five twigs had been attached, showed 
the scale fungus distributed upward from points of infection to distances 
varying from six inches to a foot, downward from sixteen inches to 
three feet, and laterally from six to twenty-six inches. 

The results of infection by means of artificial cultures were equally 
favorable, and on the whole more marked, owing especially to the fact 
that pieces of the culture medium remaining on the tree continued to 
grow the fungus and to produce the spores for an indefinite time. On 
one tree, for example, the scales on which were infected June 17th by 
smearing on a thick paste of spores from a culture of broth and corn 
meal, the fungus had made a visible start by the 5th of July. A few 
scales were then dead with a noticeable growth of the fungus, and by 
September rst this growth had become very profuse spreading in various 
directions from two to four feet from the point of infection. On an- 
other tree, similarly treated at the same time, the fungus growth Septem- 
ber 1st (about two and a half months after infection) had become very 
profuse, extending downward more than six feet and upward about 
sixteen inches and crossing an air space of at least three feet. The 
infection material was still growing in good condition and bearing large 
numbers of spores. 

On the final visit of the season, made by Mr. E. B. Forbes to 
Sparta November 2d, it appeared that there had been no great increase 
in the growth and abundance of the fungus since the September inspec- 
tion, but that in a number of cases it had spread from limb to limb in 
such a manner as to suggest that the spores had been conveyed by the 
blowing of rain drops in a high wind. An occasional washed-out 
appearance and pale color of the fungus suggested the probability that 
the recent weather had been too cool and wet for its rapid spread. 

The fact should be carefully noted that however generally the fun- 
gus was distributed, it was easy to find everywhere in the infected area 
scale insects still living and apparently not invaded by it, and even 
young scales crawling about in considerable number. It remains to be 


276 BULLETIN NO. 56. [ July, 


seen, consequently, how completely even thoroughly infected areas may 
be cleared of the scale by this fungus, since it is possible that only those 
scales which were in some way comparatively deficient in vitality were 
actually destroyed by the parasite. Contrary to this supposition we 
have only the observations made in Florida, where, again, it is not 
impossible that other and inconspicuous causes have conspired with the 
Spherostilbe to reduce the number of the scale. 

No instance could be found either at Sparta or at Richview of the 
appearance of the fungus on trees not immediately infected by Mr. 
Forbes, a fact doubtless due to the hard and tenacious character of the 
fruiting growth, which is such that the spores of this fungus are little 
likely to be carried by the air. Doubtless, however, after a time birds and 
insects passing from tree to tree would effect these transfers accidentally. 
On the other hand, it is but little work to snip off twigs from an infected 
tree and tie them to branches of those adjacent, thus securing and has- 
tening the infection process which a single season should suffice to make 
general on any badly infested premises. Indeed artificial cultures are 
so readily made in quantity and capable of being so rapidly applied 
that it would be a matter of little difficulty to treat a large orchard com- 
pletely, provided only that the supply of the cultivated fungus could be 
had by the orchardist. As the cultivation of this fungus parasite 
requires the expert methods of the bacteriological laboratory, it is 
beyond the reach of the farmer, who must depend upon the simpler 
method of infection except where the state or some private expert can 
furnish the fungus cultures to him as required. 

Thinking it possible that scales killed by the fungus would be gen- 
erally removed from the tree, and the dormant fungus with them, by 
exposure to the winter weather, I took measures to prevent a removal 
by this means of all the fungus growth upon infected trees by having 
selected portions of the infected surfaces on each tree wrapped with 
cloth early in November, to be left on all winter. I have thus made 
sure that each infected tree will have upon it a considerable area of the 
fruiting fungus in the spring in condition to renew the infection in 1899. 

Attempts at infection of the San Jose scale with the new fungus 
(Microcera sp.) detected in the Rose Hill orchard in northern Florida 
were not wholly successtul, owing perhaps in part to the small amount 
of the fungus available for experiment. Applications of a culture made 
on corn meal and beef broth were so far successful as to infect the 
scales to which the spores were applied, but there was no considerable 
spread, in the single experiment made, from the infected area to the 
adjacent scales. : 

As aresult of this field work with the above-mentioned fungous 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. CB 


disease of the San Jose scale it is evident that the distribution of S. 
coccophila under conditions prevailing in southern Illinois this year is 
likely to prove a valuable adjunct to more energetic measures for the 
destruction of this insect. Indeed, we may go so far as to say that if 
the scale should finally become a permanent resident in this state, it is 
quite possible that this and similar enemies will forma permanent check 
upon its multiplication such as to reduce its injuries to comparative 
insignificance. It must be noted, however, that the summer of 1898 
was favorable to the growth and reproduction of this fungus species, 
both with respect to temperature and rainfall. An abundance of rain- 
fall was, in fact, shown by my laboratory culture experiments to be 
indispensable to the profuse fruiting of the fungus, cultures made on a 
comparatively dry medium often growing freely but remaining sterile 
for weeks, while those made in a saturated atmosphere would fruit with 
excessive abundance within four days from the sowing of the spores. 
In a dry season, consequently, we cannot expect a rapid spread of this 
fungus from scattered infection points. 


FIELD NOTES ON FUNGOUS INFECTION. 


More definite details with regard to the spread of this fungous 
infection in the field are presented in the following items abstracted 
from the notes of Mr. E. B. Forbes, the Assistant in charge of the 
experiments. 

Neighborhood of Sparta. 

Orchard of J. M. Temple.—Twigs and bark of oak from Florida 
bearing infected scales were tied April 30, 1898, to seventy-six trees in 
this orchard. May 27th, a large number of scales were examined 
microscopically, but no positive case of death from the fungus was 
found. <A few dead scales were detected near the infected places, but 
they either contained no fungi or a fungus not resembling Spherostilbe . 
in any form known to me. 

July 6th, examined trees infected April 30th and May 2d with 
Spherostilbe coccophila. In every case where scales were abundant and 
the infection material thrifty and plentiful the fungus had spread from 
the bark or twig tied to the tree. The growth was nowhere profuse, nor 
was it even generally present on the scales in the immediate vicinity of 
the infection material. A slight start had been made in quite favorable 
situations, but where only a few scattered scales were present no growth 
was made, and in no instance had the fungus spread from the immediate 
surface originally infected. 

September ist, fungus growing everywhere vigorously. Sometimes 
-spread downwards as much as five feet, and on laterals as much as one 


278 BULLETIN NO. 56. - [ July, 


foot, though upward spread is less than downward. ‘The spores are 
evidently carried by rains and no spread across an air space was here 
noted. On one tree six inches in diameter I placed originally four 
pieces of infected material. The fungus had now spread from one 
piece downward two feet, as far as the patch of scale extended, but 
upward not at all. By no means all the scales were killed, however, on 
the area showing the fungus growth. From another piece the fungus 
had spread upward on two branches a foot and a half, down on one 
branch two feet and a half to the trunk of the tree, and out to an equal 
distance on a lateral branch. From the third piece it had gone down- 
ward three feet and a half, out six inches on a twig, but upward not at 
all. From the fourth piece it had spread upward six inches and down- 
ward a foot and a half. On another tree, five inches in diameter, to 
which six pieces of bark had been tied, the spread of the fungus has 
been so general that it cannot now be traced. Except for the smaller 
and upward twigs and branches the tree is now thoroughly infected. In 
some cases the fungus must have gone laterally as much as six feet or 
else the spores were carried across an air space. In another tree, seven 
inches in diameter, to which five pieces of the infected material had 
been applied, the fungus had spread from the first piece eighteen inches 
upward at an angle of 45°; directly upward six inches; ten inches up- 
ward on another branch at an angle of 40°; and downward fully three 
~ feet.” From a second piece it has gone downward twenty inches and 
thence out on a lateral twenty-six inches. From a third it had spread a 
foot obliquely upward and ten inches horizontally. From a fourth it 
had gone upward a foot on three branches and down sixteen inches. 
From a fifth it had spread upward six inches, down two feet to rough 
bark free from scales, and out sixteen inches on a lateral branch. 

November 2d, wrapped with cloth strip and tied with string one 
spot on each infected tree. No great increase in quantity of fungus 
since my visit September rst, although in a number of cases the infec- 
tion has gone from limb to limb in a way to suggest that the spread has 
been due to the blowing of spores in rain drops from an infected sur- 
face to one previously free. In some situations the growth has a faded 
color and a washed-out look, from which I am led to suspect that the 
weather has been too cold and rainy fora presage growth and rapid 
spread of the fungus. 

Orchard of James Wood, J/r.—May 28th, twenty-six trees infected 
with Spherostilbe grown on corn-meal batter. For a description of the 
method of application of this fungus culture see page 274. June 2rtst, 
found in this orchard a single scale which had died from the fungous 
infection. In this tree the cloth wrappers were accidentally overlooked 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 279 


and had remained in place since May 28th. ‘Two clubs of conidial 


spores were borne by this single scale. July 6th, conditions as to fungous 
infection the same as on Mr. Temple’s place, already reported. Sept. 
2d, Spherostilbe growing well in this orchard. Nov. 5th. To-day 
placed cloths for the protection of fungus on trees. 

farm of John Robinson.—June 17th, a single tree infected by 
smearing on conidial spores of Spherostilve in a thick paste made from 
culture on corn-meal and broth. Kept moist forty-eight hours with wet 
cloths. July 5th, very few scales dead from fungous infection. Disease 
has not spread far. No spore masses observed. Sept. 4th, growth very 
profuse; spread from source of infection in various directions from two 
to four feet. 

Another tree infected by tying on pieces of fresh fruiting culture 
grown on corn-meal and broth. June 2oth, this infection material 
riddled by ants, but fungus growth not eaten. July 5th, slight start of 
fungus near point of infection. Bears immature conidial spores. Sept. 
Ist, growth very profuse, extending downward over six feet and upward 
sixteen inches. In one place spores had been carried across an air 
space of three feet—probably by birds, insects, or rain. Culture 
material originally applied to the tree still growing in good condition. 
This is the most successful infection experiment I have seen, the growth 
probably being the most profuse because of an abundant and constant 
supply of conidial spores continuously developed from the original 
infection material. 

Richview, L70. 

Farm of James Newcome.— June 23, 1898, the San Jose scale 
on thirty trees was infected in this orchard with material grown on 
meal and broth, applied directly from the culture flask without 
ever having been dry. The conidial spores had been mature for about 
two weeks. The gummy mass of the culture was simply smeared upon 
the tree with a little water, and the branch treated was wrapped with 
canvas which was allowed to remain upon the trees for three weeks. 
The trees treated were not very badly infested, and were scattered here 
and there through a large orchard. There was consequently little 
opportunity for the fungus to spread from tree to tree. 

July 13th, when the first inspection was made, the fungus had 
started in every place, and it had already formed conidial knobs in 
several places, although generally its occurrence was made evident only 
by a white mycelial growth around the edge of the infected scales. 

August 31st, a careful inspection of a number of trees selected at 
random was made. On the first tree examined the infection was _ prac- 
tically complete where the surface had been covered by a cloth band, 


280 BULLETIN NO. 56. [ july, 


every scale showing the red growth of the fungus, which had also spread 
down the branch about six inches. Scales of all sizes were attacked, 
but there was no apparent spread upward or to the adjacent branches. 
The external growth was most commonly in the form of erect clubs or 
knob-like protuberances, but sometimes in that of a thick welt surround- 
ing the scale. On another tree the fungus had spread very profusely 
along the limb for about thirteen inches. On one, where the scale was 
very scarce, it had spread but three inches; on two others twelve 
inches; and on still another fifteen inches. On the next tree examined 
it had spread two feet on a main branch, and also slightly upon lateral 
twigs. On one tree carefully examined it had grown down a main 
branch for about ten inches from a profusely infected area, and laterally 
from a little below this area about an inch. Here, as elsewhere, the 
fungus was most abundant upon the spots originally treated. ere 
several pieces of paste remained with the fungus fresh and apparently 
still growing. November ist, when the winter bands were put in place, 
there had been little if any extension of the infected area, and the growth 
generally seemed to be somewhat less vigorous than on August 31st, 
probably because the very heavy rains had washed away the spores. 


EXPERIMENTS WITH INSECTICIDE SPRAYS. 


During the intervals of other field employment a few minor experi- 
ments with insecticide sprays were made by Mr. E. B. Forbes in the 
infested orchards near Sparta, Randolph county, in the months of June 
and July. No final conclusions were reached, but as the work was thor- 
oughly and carefully done the results are deemed worthy of report. 

June 17th to 2oth, pure kerosene was applied to fifteen peach-trees, 
sometimes with the ‘‘Eclipse” sprayer and ‘‘Deming Vermorel” nozzle, 
sometimes with the ‘‘ Success” sprayer and ‘‘ Bordeaux” nozzle. The 
results were in every case unsatisfactory. If applied in sufficient quan- 
tity to kill all the scales the trees were usually so severely injured that 
they were dead by September ist, or if not dead their vigor had been so 
impaired that they had been very heavily attacked by the fruit bark 
beetle (Scolytus rugulosus). In one case a peach-tree thus sprayed had 
borne a good crop of fruit and held its leaves without apparent injury 
until September rst, but its bark was everywhere peppered with the 
punctures of the fruit bark beetle, from which particles of gum had 
exuded in such quantity as nearly to cover the surface in many places. 
In but two cases had the trees escaped such injury, and in these only 
the scales exposed to direct contact with the spray were dead, all con- 
cealed or protected in any way remaining alive and producing young 
continuously. 


1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 281 


- Three small sets of experiments were made with mechanical mix- 
tures of kerosene and water, the Success sprayer and the Bordeaux noz- 
zle being used. Mixtures containing five, fifteen, and twenty per cent. 
of kerosene so applied did not hurt the trees and neither did they kill 
all the scales. A thirty per cent. mixture applied to a single tree July 
6th killed very nearly all the scales (living individuals being very rare), 
and did not visibly hurt the tree. This was, however, so nearly dead 
from scale-attack that the effect of the spraying was left somewhat in 
doubt. 

Tests of the ‘“‘Success Kerosene Sprayer,” bought of the Deming 
Company, Salem, Ohio, made with a view to determining the accuracy 
of the percentage indications of the scale, gave results showing that the 
percentages varied considerably according to the action of the pump 
and the fineness of the spray. With the indicator of the dial set at 10% 
the amount of kerosene in the mixture would vary from 7.5% to 13.13%, 
the lower percentage when the pump was vigorously worked with a very 
fine spray, and the higher when it was vigorously worked with an open 
stream. With a fairly fine spray and moderate action the kerosene in 
the mixture was 12%. With an indication of 5% of kerosene the actual 
delivery varied from 4.07% to 6.92%. Additional details of these tests 
are given in the following table: 


Test oF ‘‘ SuccESS KEROSENE SPRAYER.”’ 

















| Actual percentage in spray. 
Indicated percentage. : Very fine spray 
Open stream, pump) Fine spray, pump Traivorker 
worked vigorously.|worked moderately. EC tiedtobely 
5 6.92 5-94 4.07 
IO IS7r3 IZ 7a5 
15 18.9 17.4 3 98 
20 22.75, 21 17 
30 32.5 30 20.5 
40 43.4 | 40 
50 48 46.6 

















Mixtures of carboleum—an insecticide sent us for experimental use 
by the Prescott Chemical Company, 134 Van Buren St., Chicago—were 
too little tried to warrant a final conclusion. One, two, and four per 
cent. solutions were without pronounced effect upon the scale and did 
no permanent harm to the trees. ‘This insecticide mixes freely with 
water in all proportions except for a heavy substance which settles to 
the bottom of the mixture as a heavy brown oil. This filters out readily, 
and the remaining liquid is then a stable emulsion of a light coffee 


282 BULLETIN NO. 56. { July, 


color. Thecarboleum should be diluted with rain water, as otherwise 
a troublesome gummy precipitate forms. . 


MISCELLANEOUS FIELD MEMORANDA. 


From Mr. Forbes’s miscellaneous notes I cull the following minor 
observations of interest: 

Male scales were just beginning to hatch at Sparta, in Randolph 
county, April 30, 1898, two winged specimens having been first seen on 
that day. Under a greater part of all the male scales examined were 
winged insects nearly ready to emerge. Of a hundred such scales ex- 
amined May sth, eighty were empty, eight contained winged males, and_ 
twelve contained pupz not yet transformed. 

Female scales had just begun to give birth to young at Sparta May 
27th. Probably none of these were more than two days old, as all were 
still in the active stage. On the other hand, reproduction had nearly 
ceased November 2d, at which time, although no active larve were seen, 
a few scales could still be found so young that it was evident that they 
had fixed themselves only a few hours before. 

Observations made in spring and early summer, especially on Mr. 


J. M. Temple’s grounds, showed that a very large number of the partly ~ 


grown young San Jose scale of the preceding year had perished, nearly 
all of those on the tree trunks and on the older limbs being, in fact, 
dead the first of June. Those on the young growth, however, throve, 
matured, and multiplied. Asa general result of observations of this 
character, it appeared that very many of the scales of 1897 were dead in 
nearly all the orchards visited, and that many of the old trees in that 
region were seemingly in a better condition on this account than in the 
preceding year. There was no appearance here of any other cause of 
death than mere starvation, due, as was surmised, to the protracted 


‘ drouth and excessive heat of the summer of 1897. 


\ 


Experiments made June 17th at blowing the young scales in the 
active stage from the surface of the tree made it evident that they might 
be occasionally detached by a very heavy wind and carried thus to con- 
siderable distances. It was noticed, however, that when exposed to 
strong wind the young scales sought the sheltered side of the limb.~ At 
this date scales were found attached and growing on ragweed (Amérosia), 
peppergrass (Lepzdium) and horse-nettle (So/anum), all under infested 
trees. Ps 
The rate of travel of the young was tested June 2oth by transferring 
ten active specimens to a piece of paintéd glass, watching them for a 
minute each, and carefully measuring the distances traversed. These 


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- 1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 288 


ranged from 1.9 to 3.4 centimeters, with an average rate of 2.75 centi- 
meters (1.1 inch) to the minute. 

Where strips of damp cloth were tied around branches of a tree to 
protect the fungus beneath, it was noticed May 28th that the traveling 
young would accumulate along the lower edge of the band in a way to 
form a yellow circle around the limb. Such an accumulation was rarely 
~seen above the band. None of the young attempted to cross the cloth. 

The only insect enemy of the San Jose scale noticeably abundant 
in the Sparta region was Pendzc/ia misella (Plate IV, Fig. 4, 5, 6), which 
became so common in badly infested orchards by November 2d that 
the number on a heavily infested tree was estimated at several thousand. 
They had, notwithstanding, produced no visible effect upon the number 
of scales in any orchard visited. The twice-stabbed ladybird (Chzlocorus 
bivulnerus, Plate IV, Fig. 1, 2), was seen occasionally, but was nowhere 


abundant. 
STEPHEN A. FORBES, 
State Entomologist. 
December 20, 1898. 


284 BULLETIN NO. 56. [ July 


EXPLANATION OF PLATES. 





iA Teele 


Map of Illinois showing known distribution of San Jose scale, 


with extent and effects of treatment. 


PLATES Ls 


Machine sprayer, with gasoline engine, triplex pump and double 


tank for whale-oil soap solution. 


PLATE “LEE 


Fig. 1. Gasoline engine of machine sprayer. 


Fig. 2. Battery of gasoline burners used under each tank for boiling 
whale-oil soap solution. 


PLATE MLV 
Parasites of the San Jose Scale. 


Fig. t. Chilocorus bivulnerus, larva. 

Fig. 2. Chilocorus bivulnerus, adult beetle. 

Fig. 3. Aphelinus diaspidis. Not a parasite of the San Jose scale, 
but closely allied to 4. mytzlaspidis, which is parasitic upon 
this scale. 

Fig. 4, 5, 6. Pentclia misella, beetle, larva, and pupa. 

Fig. 7. Spherostilbe coccophila. 


*Figures I, 2, 4, 5, and 7 areoriginal. Figures 3 and 6 are re-drawn from Bulletin 
No. 13, n. s, U. S. Department of Agriculture, Division of Entomology, ‘‘The San 
Jose Scale: its Occurrences in the United States, with a full Account of its Life 
History and the Remedies to be used against it,” pp. 51 and 52. 





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| @ Exterminated. ‘ 








1899. | “WORK ON THE SAN JOSE SCALE IN ILLINOIS. ur 20S 

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286 BULLETIN NO. 56. [ July, 


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1899. | 

















WORK ON THE 


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